As for the biceps, there isn't much difference. Both fit nicely. But yes that right forearm is larger than the left, and the issue is with ATA that flat area is already defined for the cover strips and you can't reduce it beyond that (or at least without having <5/8" cover strips which would look odd). My plan is to leave as much return edge at the top and use foam to keep it from moving around. I would love to hear if anyone else has any suggestion.