I'm not sure about US vehicles but here in Canada, we can get original paperwork on vehicles assembled in the Oshawa, Ontario plant. (I have this sheet for 2 old cars I own) This document will tell me what the serial number should be on the cars I presently have in my garage at home. This is not only the VIN but also the engine and transmission serial numbers. My Chevelle has the exact number on the GM document that the engine has stamped on the block. These numbers match, (it's a hi-perf 396) and the fact that these numbers match makes it more valuable to some people, also makes the book value higher.
As far as I know, the American assembly plants didn't record and store all these numbers until much later than here in Canada.
