I make mine from Bondo fiberglass resin from the auto parts store.
I get a nonstick pan, glue the baits down in it, spray the pan and baits with cooking oil, mix up the bondo and gently pour it over the baits and fill the pan.
I then go away for 24 hours. When I come back I dump the pan, pull the baits out and smooth the edges with my dremel tool.
They aren't great but they are functional. I tried to add a pic but it did not work this time.