if that doesn't look/feel up to it then give the shoe goo stuff a go.
Bostick 2402, two part chloroprene adhesive.Sticks on contact once tacky, extraordinarily strong, used for edge gluing neoprene for divers drysuits and attaching boot soles.Clean thoroughly with Isopropyl Alcohol (Surgical Spirit BP) or Acetone first, be very careful not to press the rand to the boot until you've got it positioned Just So, because it will stick and stay stuck.
Hey SEDur - maybe start a new thread 'group buy of Send knee pads' - maybe with a deadline of end of Aug etc.. And see how many folk are interested..? Seen that done quite a bit on other forums (car ones) for getting overseas parts etc.. Might even get a bulk discount!
Easy enough to order from Send, but you'll most likely have to pay import duty (we did).