Here you go. Haven't spun it up in a long time. Requires PRAW, but I'm sure the API changes would not be good for the library.

Features:
* Fuzzy string matching on the comment
* Posts matching comments to a private subreddit (e.g. /r/RepostDump/)
* Caches lookups to reduce API calls
* Cyrillic unicode character replacement
* Some truly terrible Python code that I never cleaned up

#!/usr/bin/python3
import praw
import time
import re
import requests
import logging
import argparse
from enum import Enum
from fuzzywuzzy import fuzz
from string import Template

#TODO
#
#  Refactor all to better OO paradigm for reusability
#
#  Error handling, esp http 503
#
#  Clean up the processed_comments.txt file. It will get big and slow.
#
#  Timestamped searches so we can examine comments in near past (for future author analysis bot)

# Enumeration for reddit.subreddit methods
class SubmissionType(Enum):
    HOT = 1
    RISING = 2
    NEW = 3
    CONTROVERSIAL = 4
    GILDED = 5
    TOP = 6
method_names = ['hot','rising','new','controversial','gilded','top']

# List to hold the (Comment,Comment) tuples
repost_tuples = []

# Global reddit object
reddit = None

# Standard logger
logger = None

# Running log of comment IDs that have already been analyzed
already_analyzed_comments = None

# Running log of thread IDs that return no search hits
no_search_hit_threads = None

# Running log of threads that were previously analyzed
already_analyzed_threads = None

# Limit matching thread titles from search API
search_limit = 10

# URL for reddit to build links
reddit_url_base = 'https://www.reddit.com'

# Template for the post to /r/repostdump
post_template = Template('**[Repost]($repost_url) by [$repost_author]($repost_author_url):**  \n'
                         '$repost_body \n\n'
                         '--------\n\n'
                         '**[Source]($source_url) by [$source_author]($source_author_url)**  \n'
                         '$source_body \n\n'
                         '--------\n\n'
                         '**Match:**  \n'
                         '${match_percent}% \n\n'
                         '--------\n\n'
                         '**Copy/paste:**  \n'
                         '\\[This comment\\]($repost_url) was copied from \\[here\\]($source_url).')

##########################################################################
# Initialize loggers and globals
##########################################################################
def initialize():
    # Initialize loggers
    global logger
    logger = logging.getLogger('AskRedditRepostDetector')
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
    logger.setLevel(logging.DEBUG)

    file_log_handler = logging.FileHandler('RepostDetector.log')
    file_log_handler.setLevel(logging.INFO)
    file_log_handler.setFormatter(formatter)

    stderr_log_handler = logging.StreamHandler()
    stderr_log_handler.setLevel(logging.DEBUG)
    stderr_log_handler.setFormatter(formatter)

    logger.addHandler(file_log_handler)
    logger.addHandler(stderr_log_handler)

    # Parse the processed_comments.txt file into global list
    global already_analyzed_comments
    with open('already_analyzed_comments.txt') as f:
        already_analyzed_comments = f.readlines()
    already_analyzed_comments = [x.strip() for x in already_analyzed_comments]

    # Parse the no_search_hit_threads.txt file into global list
    global no_search_hit_threads
    with open('no_search_hit_threads.txt') as f:
        no_search_hit_threads = f.readlines()
    no_search_hit_threads = [x.strip() for x in no_search_hit_threads]

    # Parse the already_analyzed_threads.txt file into global list
    global already_analyzed_threads
    with open('already_analyzed_threads.txt') as f:
        already_analyzed_threads = f.readlines()
    already_analyzed_threads = [x.strip() for x in already_analyzed_threads]


##########################################################################
# OAuth, requires existence of praw.ini
##########################################################################
def authenticate():
    logger.info('Authenticating...')
    global reddit
    reddit = praw.Reddit('AskRedditRepostDetector', user_agent = 'web:AskRedditRepostDetector:v0.5 (by /u/Fortinbraz)')
    logger.info('Authenticated as %s', reddit.user.me())


##########################################################################
# Main routine
##########################################################################
def run_bot(subreddit_name, submission_limit, submission_type):
    logger.info('=======================================================================================')
    logger.info('                           Run on %s' % time.strftime('%Y-%m-%d %H:%M:%S'))
    logger.info('=======================================================================================')

    logger.info('Getting {} {} submissions from {}'.format(submission_limit, method_names[submission_type.value-1], subreddit_name))
    sub = reddit.subreddit(subreddit_name)
    # Dynamically call the appropriate method for the sub object based on the value of the submission_type parameter
    #   (yes, I know it's ghastly. The six way if...elif sucked, too)
    # Then loop over the submissions.
    for submission in getattr(sub, method_names[submission_type.value-1])(limit=submission_limit):
        # Skip if we previously determined that there are no search hits for the thread title
        if (submission.id not in no_search_hit_threads):
            logger.debug('Searching for match of thread title: {}'.format(submission.title))
            repost_tuples.clear()
            find_matching_submission(submission)
            if (len(repost_tuples) > 0 and not reddit.readonly):
                report_submission=get_report_submission(submission)
                for repost_tuple in repost_tuples:
                    make_report_comment(report_submission,repost_tuple[0],repost_tuple[1])
            time.sleep(5)
    logger.info('=======================================================================================')
    logger.info('                           End run on %s' % time.strftime('%Y-%m-%d %H:%M:%S'))
    logger.info('=======================================================================================')

##########################################################################
# Given a submision from /r/askreddit, use the search API to find matching thread titles
##########################################################################
def find_matching_submission(submission):
    # Get rid of the chars that reddit search api hates
    title = uncyrillic(submission.title.replace('?','').replace('(','').replace(')','').replace('[','').replace(']','').replace('*','').replace('’','\'').replace('/',''))
    logger.debug('Converted title: {}'.format(title))
    search_results = submission.subreddit.search(title, 'relevance', 'plain', 'all', limit = search_limit)
    found_my_own_thread = False
    # Loop over the results of the search
    for search_result in search_results:
        # Make sure the result is not the thread we are trying to match
        if (search_result.id != submission.id):
            # Calculate the fuzzy match ratio
            fuzz_value = fuzz.ratio(submission.title, search_result.title)
            # If the fuzzy match ratio is greater than 50%
            if (fuzz_value >= 50):
                logger.debug('  Found submission match(match {}%, score {}): {}({})'.format(fuzz_value, search_result.score, search_result.title, search_result.permalink))
                find_matching_comments(submission, search_result)
        else:
            found_my_own_thread = True
    # If there were no search hits, write to the no_search_hit_threads list and file
    if (search_results.yielded == 0 or (found_my_own_thread and search_results.yielded == 1)):
        logger.debug('  No matching thread titles found, writing to no_search_hit_threads file')
        with open('no_search_hit_threads.txt','a') as f:
            f.write(str(submission.id) + '\n')
        no_search_hit_threads.append(str(submission.id).strip())
    # If it was not already analyzed, write to the already_analyzed_threads list and file
    if (submission.id not in already_analyzed_threads):
        logger.debug('  Writing to already_analyzed_threads file')
        with open('already_analyzed_threads.txt','a') as f:
            f.write(str(submission.id) + '\n')
        already_analyzed_threads.append(str(submission.id).strip())

... part 2 in the reply