Coneboy,
I hope someone will give you a more direct answer, but following is an example of what I have found out about replacing hard to find parts on an older truck. After an unsuccessful application search for a replacement brake/clutch master cylinder, I found one based on part characteristics - In this case it was shape, bore diameter, and bore length. This is not easy, but it has worked for me. Good luck with your '46.
JRMunn
