Thanks for the fine advice you gave me about installing my mirror on my thick bike helmet down here in Austin, TX. Now like to report back that the mirror has been a welcome asset. I have a very decent rear view, aided by the sizable mirror, good ability to place---far superior to the several other helmet mirrors which I went through. You are welcome to use any part of this on your website if desired.
Here wishing you all very well and to thank you for this contribution to bicycling!