There is a large group of parts manuals for sale on e-bay. This is the largest group I have ever seen with no repeats. These would be great for reference material. Condition is not great as far as collectables go, but for reference material they would be great. The year range of the manuals is also unusual... The manuals after the model T era are not very common. I have them all but one, so I will not be bidding. Hope someone gets them that will use them as a research tool ... I have used my manuals many times to help verify a parts year range or introduction date.
https://www.ebay.com/itm/FORD-Model-T-1920-1933-lot-of-30-MANUALS-PARTS-BOOKS-pr ice-lists/282810669021?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l264 9
I don't think Profits and part prices would be of much value for research. Parts catalogs, on the other hand would be. With an actual parts catalog one could check interchangeability and coverage of a particular part. I have saved parts catalogs for non-T vehicles for years, but have thrown away other books like flat rate manuals.
Just my 2 cents worth.
I agree that the profits manuals will not be much good for research, but the price lists of parts do have a lot of info in them.