Should work perfectly to use the KOTCS jacket on ROTLA Indy...and will look MUCH BETTER IMO, but you will have to break off the arms. I had to do that with my ROTLA PF to get the Sovereign custom 1/4 jacket on.
To do it I put the PF on the sofa (soft surface to lie it on), wrapped the arm that had to get broken with a dry dish cloth (so I wouldn't damage, leave marks on the clothes), then carefully hit it with a hammer in an area that would be covered up by the clothes once I fixed it (like the upper arm or elbow area). had to hit it a couple times to get it to break, but it broke cleanly and worked well.
For ROTLA, I would say you probably want to break the idol holding hand either just above, or just below the elbow. For the whip holding hand, somewhere nearer the shoulder so the long arm comes out as one piece.
For KOTCS it should be easier since the whip holding arm is already in 2 pieces, so you only have to break the arm with the hand on the hip. For this I would try to use the hammer towards the upper arm above the elbow coming at it from an angle over the torso, trying to knock the arm 'away' from the body. That way you hopefully won't damage the hip hand.
I've had to glue a couple of PF's back together (Count Dooku's boots and ROTLA Indy's arms) and krazy glue has worked well to hold both so far.
Hope that helps. Good luck, and be patient. Don't swing that hammer too hard. You're just using it to 'knock' the pieces off, so use it closer to the polystone and hit more times gently if need be.
