Heck, it wouldn't be a PJ thread if we didn't hijack it and we were just killing time 'til you came back. (anyway, cenracer started it!!)
Put the angle grinder down and back away from the chassis!! Why not start with the things that can be replaced first! A new flywheel is a couple of quid, a new JT chassis, well thats a different story! If the flywheel experiment doesn't work, I would pick up one of the new CEN chassis' before cutting into the JT. Collectors items now mate!