You should look for the originals, or perhaps they're reproduced.
Do you have any restoration parts catalogs?

I did have a 1928 car and remember a little about door handles... if I were in your situation I'd find the right part for the job and not try to substitute or modify.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-