Very sorry regarding you father. My prayers and condolences. While I know it's not exactly the same my Grandpa just passed this Christmas and I can tell you from these passed few months of cleaning, I sure do wish he would have labeled the keys!!!

. Like you said. We are scared to get rid of any. You might find a locked file cabinet, he had several full gun safes, lock boxes, barns, tractors, 2 boats, you name, it seems like everything of any importance has a key.
Thanks for the link

. Reading along that was going to be my question. I'm definitely gonna start a list of keywords and will be doing the same. I love that.
Thanks - He lived a very full life and came within a week of 90. Better than most of us will do.
I learned a lot from going through his and my mother's stuff.
Not only that, my Mother in-law was killed in a car accident a couple years ago so my wife and I have had some experience in settling estates.
I am 56 but I am already trying to organize things for my wife or whoever has to settle our affairs.
Getting an update will and pre-paying for cremations was done was first.
I also made a binder labeled "I'm Dead - Start Here"
I have a nice WWII gun collection - I made a spreadsheet with serial numbers, historical significance and an approximate value. I also listed a couple antique gun dealers I have dealt with that buy complete collections at fair prices.
Made sure two trusted people have the combos to the gun safes.
Filed all the vehicle and trailer titles in one manila envelope in the safe.
Life insurance policy, DD-214, Birth Certificates, Passport, and a copy of the will is also in their own manila envelope in a safe. The original will is held by the attorney's office.
All keys labeled.
As silly as it sounds, I made a spreadsheet for the house and pole barn breaker panels. Dad's didn't have any labels - wasn't that fun figuring out.
Made a spreadsheet of all the large maintenance items we have done since moving back - roof, flooring, kitchen, bathrooms, plumbing, electric, pole barn. It has the date and who did the work. I also included paint codes for all the paint we have used.
Scanned in all major purchase receipts, banking and investment docs I think are important, backed them up on a hard rive that's in a safe.
Filled out a password book with not only user names and passwords but all bank and utility account numbers.
Spreadsheet with phone numbers to all utility providers, banks, investment firms, etc.
Being retired, I spend a couple hours every week keeping it up to date.
I just try to think back what was a pain in our a$$ and try to make it easier on the executor of our estate.
Morbid - Maybe?
Practical - Absolutely IMHO!