I'd like to put one of the MT.o patches on my current computer/EDC bag (a Booq Boa Nerve S). The thing is it has no velcro attachment points. I thought about sewing the loop part on but the outer fabric is waterproof and I don't want to ruin it. A couple professionals I asked just wouldn't take it since the bag's structure makes it a pain and they can't guarantee the end result (they'd have to take the flap apart, sew the loop part, put the flap back together, etc.). I did some google'ing and came up with a couple of velcro adhesives but a visit to the local hardware stores disappointed me; apparently these things are too "exotic" in my part of the world.
I'm now thinking about either sewing it by hand myself and then applying some seam sealer on the threading, or trying harder to find some velcro-fabric adhesive. Do you know of any adhesive and/or seam sealer available in Europe that could do the trick? Any ideas or advice if I take the first approach of hand-sewing?