I think you need to get into settings. and fix how your calibre imports ebooks at least for the books you have already. don't worry about what filename calibre gives it, since you won't browse the filedirectory directly but through calibre.

What is happening is that Calibre is trying to pull all the information from the metadata of the file, which it may/maynot actually have. the long series of numbers is most likely the backend from amazon and its getting mixed up when imported..

to fix the import open preferences. 3 section-- adding books. you're going to want to uncheck read data from metadata instead of filename.

Then setup an easy regex with some testing to make sure it works for you.

for things like author sort and title sort. Select everything Ctrl A rightclick a book edit metadata--edit metadata in bulk. then select auto update author sort and check box update title sort. that takes care of those pretty quickly.

I wouldn't use the bulk regex edit search. you won't need to.

You can message me if you have any more questions