A poll on a parallel thread has revealed as much as we can expect for the moment, so let's move right along: [I've posted this same message on that thread too.]
I'm a purist when it comes to authenticity, but also a realist that sees room for improvement, or we wouldn't be making new door handles in the first place!
I've spoken to my foundrymen over the past weeks, and while it is possible to make the handles in stainless steel, they would be more expensive as that would require a different furnace process.
With reasonable pricing in mind, my first vote would be for an original-style bronze handle, finished and chrome plated, yet better that the original, with the option of ordering it with, or without a new splined shaft.
Second choice is as above, but made in stainless steel.
I hope to report back next week with ballpark pricing on both these options which should narrow our choices down a bit more.
Regards,