update:
biggest male grew spectacularly in only a months time in the new bigger tank. Much bigger/heavier, and he colored up very well. (not *quite* as much as the females of course) Rules with an iron fist, such is the salvini temperament.
I reintroduced the largest female to him in the big tank and they took to each other immediately. The excavating of pits has begun! wish me luck trying to keep the darn plants in the ground.
sidenote: a friend is trying to rehome a synodontis eupterus to me as he doesn't really have the space for it (he got it from a local lady who underestimated its size to him) - you guys think it could survive the salvini pair ok when egg time comes? He reckons it's about 9" right now.
I have space to remove the other current inhabitants of the tank if needed, but I wouldn't really have another spot to put the featherfin. So he'd need to be able to tough it out. Tank is 120g on a 5ft long footprint.
thanks! I'll get pics up of the salvini pair when I get a chance.