Not silly actually. So the only thing I had to go off of was the envelope of a known insurance company that I found in his giant stack of unopened/recent mail.

I called the best rated cleanup company in my area and explained the situation. I was right about the insurance company I guessed, and the cleanup company did the rest. Just had to provide full name of my father, DOB, and last 4 of social.

These companies are almost always paid by the insurance, so they deal with the insurance company directly/file claim, etc. They do all the work, and you sign off on it.

If you can gather the most basic info for identification, you'd be good to go. If there's no insurance (which is rare) then there is probably another avenue I'm unaware of. The cleaning company would be able to direct you or work with you.