Here is a web site that you can order these suction type mirrors from.
http://www.vintagecarparts.co.uk/part.phtml?PartID=2651 They are available in two sizes but they dont tell you other than large and small. I would opt for the small. One British pound equals about $1.88 in US dollars. With a min. order looks like the best way to order these are to have your club buy a large quantity and resell to the members.