There is nothing wrong with selling or offering this type of paperwork. It is what is done with it that matters.
ebay/the Internet is covered in reproduction and original paperwork for sale and personally I believe this is a good thing.
A lot of the information we talk about here or have a personal knowledge comes from such items. It enriches our lives and maintains a history.
Holden legal would laugh at you or at least dismiss any such caller.

Also remember nobody likes a dibber dobber!