Showed these pics to my father, old trapper that he is. Said you should boil the traps clean. Thats how it found them all, by scent. My rec would be to try eggs as bait. Have had no luck with carcasses but a pile of eggs drew them right in.
Could you use conabears? Something wise enough to evade a leghold might get caught easier in one of those. Or its stake out time with nightvision googles.