Drifting back... Now back to the subject.... Could a SW9 fit on a Micro Trains SW1500 and use the factory handrails?
Yes, the LL SW9 shell will fit on the MT SW1500 drive. As far as using the handrails, they are top sill mounted vs. side sill mounted so you would need to drill new holes...if the length even works out to be the same or is close enough.