You probably would not be the first to do so. I’ve found all sorts of hillbilly stuff on non working guns I’ve bought. Kinda forces one to learn! I would actually do something similar though, if in a pinch, which would be to find some very slim (slimmer than a credit card), smooth plastic (such as a plastic package that new grips or a magazine might come in). Cut a piece to shape, slightly wider than the trigger bar, then super glue it to the backside of the plate. Then add some grease to the outside of the trigger bar where it would rub the new plastic. Not a long term solution, but should work for a while while sourcing a new plate.