I bought a reproduction door lock for my 53 from Classic Parts. My “push rod” shaft was too short as well. I cut a piece of 5/16” stainless tubing , egged it slightly in my vise and then hammered down over the protruding end of the push rod. I made it about an 1/8” longer than push rod end. Works great now, but when buying things they really should just work.
Junk.
