When I purchased the body of a Stanley #78, I figured I would either make new parts, or buy them. Stanley has replacement parts, but what I would need would probably be over $30. That's not much considering that a plane with all its matching parts costs quite a bit more than that (because of collectors).
I realized that a old and almost completely used up plane blade($1) would be perfect.
Then, I made a lever cap from 1/4" aluminum(free from my dad). the tensioning screw is just a piece of threaded rod with a slot cut in it because I didn't have the right screw.
Here are the results made with a fence board tacked to the piece.