Both MTH and K-Line published a book detailing production in their early years. MTH went up through year 2000 which leaves the last 20 years. K-Line's book went up through 1998. Generally their later catalogs are for sale on ebay. I have had difficulty trying to fill in the gaps for k-Line production. MTH, a lot of catalogs out there. There are sites that list a lot of the Lionel production. There is not a one site answer all questions that I know of.