Hello there, There isn't much too the clutch arm. Basically the clutch arm has a cam on it and a rod with a ball a bearing followed by another rod. When you pull the lever, it actuates the cam which pushes the rods to overcome the clutch springs which is holding the clutch plates down. Based on that description, assuming nothing else has changed, either you haven't adjusted the clutch cable enough, or the fact you've pulled the cam out may have caused the push rod to take it's gap, meaning the cam is no longer engaging the rod. I am not sure if that's even possible, I have always put the rods in before the clutch arm and I've never had an issue. So it's probably that you haven't adjusted the clutch cable properly.

I’ve had someone listen to it as in person is obviously way better then a compressed video and think it may be the piston rings

PS Same issue, bottom of gasket is dry and the top has oily wet channels…

Yeah it's worth checking that first. I haven't done a set of DT cases for a while, I've never done 200 cases.