The Fro Joy Babe Ruth cards were counterfeited in the 70's, but the counterfeits were not of the factory cut singles, instead from counterfeit singles. People cut the fake sheets and sold the cards as singles (still do) or sold the entire sheets as if they were authentic. Some of these, with the dotted cut lines, perfect centering, poor image, etc can be found on ebay now. They're poor reproductions at best, but they're from the 70's, so do give an appearance of "old."
Then along came repli-cards, which were much better reproductions. Anyone familiar with how to spot a fake sheet or single cut from a fake sheet could still be ripped off with these and may have led some people to believe a printing plate still exists. But upon closer inspection, although they did a good job of printing the dark sections of each card, they did a poor job of printing the lighter areas. Take the #3 and #4 cards for example, fake next to a real card pictured below (scanned side by side with the same settings before extracting specific areas for comparison):
