Anything you do would probably be a replica of the original. Like the 74, it's better to let her rest and remain historical.
How about getting hte 318 done instead? She's already had work done on her. Might as well get her done before starting other projects.
It's really neat that the CRRM will have 346 and 20 operational and eventually 318. I'm talking locomotives owned by the museum and not just parked there. Oh, and you have geese 2, 6 and 7, pee-wee #3 and the #50. That's a pretty full roundhouse. Having more than one locomotive available for trains really helps. Having the former loop equipment there allowed the 346 to get rebuilt without the neighbors "forgetting" what a steam whistle sounds like.
Say, are they still really toning down the whistles there? When I was last at a steam up over 10 years ago they were cutting back on the whistle so not to disturb the neighbors. Kind of took the fun out of "playing the whistle" ya' know.