The original mirrycle mirror is still in production. I had one on my touring bike for almost 20 years. I always thought it was a great design.
I recently had an issue a new mirror, the people were kind and generous. I think there a great company.
http://www.mirrycle.com/original%20_mirror.php
Oh great. There goes my corner the market strategy... But you are right on the money. For older road bikes, these mirrors cannot be beat in my opinion.