Thanks John. I grabbed the flange earlier and it has very slight in out movement, I'm not a pro but I wouldn't call it excessive...very minor. This is the left side, all studs have been changed to right hand at some point, not by me. The knurl (?) was stripped on one stud so it was loose in the flange, hence the change when I put the new wheels on.
I'll try your other suggestions next. It only contacts under load (right turns), if axle or drum was warped shouldn't it rub with or without load?