Just report them

I know of no reason why a seller could not sell a copy of a pattern or picture or ??.     As long as it clearly states it is a copy.

A number of years ago, ebay specifically mentioned photocopies in its prohibited listings policy, but this was removed some time ago. My main product line has been decimated by unauthorised Chinese digital and scan copies that infringe current copyright and trademark legislation, but the only people who can report this to ebay,s Vero programme are the copyright holders themselves.

Many companies simply cannot be bothered and ebay will not take action unless the copyright holder complains. As for older and vintage items, no longer protected by copyright, it is open slather. ( so long as the copy is noted in the description )

My answer has been to develop alternative product lines that cant easily be copied.

And maybe the OP's items are more valuable to the buyer who is a collector of original patterns.    Not the buyer who just wants a single dress pattern to make a dress.