Thanks for all the suggestions about where to get the velcro but I already have a number of rolls of velcro tape that I will be using. When I use it up I'll try some of the suggested vendors.

I don't think wear will be a problem as the velcro tape is to hold in fuel tanks and, hopefully, I won't need to remove them very often! Just trying to find out which side (hook or loop) is more permanent when glued...