The SCD Standard Catalog has listings for some fakes, at least two that I know of for Topps. Someone got a bunch of those Topps Surf books and cut out the small player pictures, which were actual card replicas, and pasted them to cardboard stamped with "Topps Promotional Sample" on the backs, and sold them on ebay as "rare" Topps promo cards. Bob Lemke included a listing for them, picturing a 61 Mantle, stating they were fakes and without value. I think the listing appears at the beginning of the 1960s Topps listings in the 2011 Catalog.
He also listed fake Pewter ingots, that were designed to look like the Topps Gallery Of Champions silver, bronze and aluminum die cut cards that came in boxed sets of 12. For most years ( they ran from around 84 to 91), Topps did produce one pewter figure with each set as an extra premium, but different pewter ingots started showing up on ebay of additional players. Why someone would counterfeit them is a mystery ( The actual silver sets do have some value). Bob noted them as fakes in the Catalog and stated they had no value.
Well, since both were actually in the Catalog, they did have some value to warped individuals like me who had to have at least a couple examples of each, which I bought on ebay. An example of the real Gallery items is below
I keep the Surf "cards" with my corresponding sets and the fake ingots with my boxed Gallery of Champions sets