Thanks for all the replies and suggestions.
I'll be trying the Sunrise Tactical offering.

The Sunrise Tactical holder arrived today and I believe it will be perfect for my needs/wants. It seems to be very well made and the non-elastic straps are easy to adjust and fit over my heaviest coat sleeve. The nice touches are the tabs that allow easy opening of the top layer window to see what's below and the nonslip liner material to help keep it in place when tightened.

Again, thanks to everyone who made suggestions.