I didn't know that about the PRS. I knew about the Ibanez Explorer, that was back in the early 80's, wasn't it?
BTW, this does bring up a possible topic for discussion; copy and "lawsuit" guitars. Back in the 80's, there were a lot of Fender and Gibson clones coming out of Asia that looked so much like the real thing that it prompted U.S. companies to take action. Fender's headstock shape is a visual trademark. You can make a Strat-copy all you want as long as it does not have the Stratocaster headstock shape. It seems like Gibson went a bit further which lead them to ultimately file suit against Paul Reed Smith for their Single Cut (and the Tremonti Signature) model and the judge agreed with Gibson's argument. There were those Ibanez Explorers that you mentioned and of course Tokai who made perfect replicas of Fenders and Gibsons. I think that they are no longer allowed to export guitars with Fender shaped heads, but you may be able to buy them in Japan.