Can't help you with a source, Dan, but I agree with your choice. I have seen a few replicas with windshield frame mounted rear view mirrors and like the look. My fender mounted rear view mirror gives me a great view of the flare in the rear fender, not such a great view of the road.
I'll keep an eye on this thread....and keep my eyes open for a source. I wonder if some of the Brittish companies might not be the best option?
Cheers!
Dugly