FAA CD - True that it will not provide a complete picture but will provide some good information. I get a CD for every ship I have owned plus those for the club. The owner always seems to have missing physical documentation (in your case none) that will show up in the CD. This usually takes ~1 week to arrive but heaven only knows how long it will take now. See https://www.faa.gov/licenses_certifi...craft_records/

Life Hour Limit - Simply do not buy this ship if it has a limit. Tthere is just no clear way to know if this is a 100h ship or a 5,000h ship. However, you might get a general idea from the records of the club it was flow at if the estate knows what club the fellow flew might take some digging. More problematic is knowing the other places the ship has flown (clubs, contests, regattas, etc). This will build up an admittedly incomplete picture but it will help point the way.

NTSB - I would also look through NTSB reports for the specific tail number and, more generally, for the make/model. If this tail number has had significant damage I would steer clear for fear of the unknown. If the model has a significant accident history then I would also steer clear.

Bottom line - You will have to start from scratch to recreate documentation and, as others have stated, a good (best?) IA will be critical to the success of this.

Best of luck, John OHM Ω