Sometimes the simplest things bring you great pleasure
You are certainly going to lose nothing but time and a minimal amount of $'s giving it a go !
I would be tempted to try and get the mech working and leave the body just as it is ... how cool would it be just to see that rusty beast running around .. a true Rat-Rod of the train world ... and hey if all else fails it would be a very quick and cheap fix just to buy a junker Marx electric for the running gear and do a motor transplant