Sell the steam, keep the diesel. Usually easier to upgrade electronics on diesels. Or you can remove the motors and use it as a dummy, and you still have the coil couplers, center rollers, lights, speaker. I converted an MTH PS1 GP9 to TMCC dummy using an LCRU I had laying around. Might have burned out one of the triac for the coil couplers, based upon something Gunrunnerjohn said about resistance of MTH coil couplers.