I've been trying to keep my '54 3B as original as can, but driving it around and I just can't stand the size of the original mirror. My eyesight isn't the best either, so I was hunting around for something that looks original but slightly bigger. I found these from TACTIC for $30 a pair. They're about an inch bigger in diameter than originals and not as dark as the mirror head I had by Kingbee. It takes a lot of scrutiny to notice they're not original size.
I haven't done it yet, but I intend to put a vintage style mirror arm on the passenger side too, but I think these would also mount to the windshield frame for people not as keen to original details. Thought I'd share.