Here's half of a Tron. What are you looking for? I think the MCR I, II, and III all use the same power supply PCB. Bob has a page on them here: http://www.therealbobroberts.net/midway.html
Thanks, I sorted out my Bally-Midway PCB's today and found I had a ton of power supplies. Some I couldn't identify, but knew they were MCR series. The photos helped thanks.