Nathan,
Fortunately I kept the paperwork with the loco. It was a NWSL 2027 Sagami, so that should help you with an equivalent. It was rated at 9100 RPM at 12V, which is a bit speedy in these if memory serves.
I've actually been finding really good motors from China on eBay, particularly 6 pole motors which have low RPM and ridiculous torque for their size. A guy on another group who repowers brass professionally is recommending this Mabuchi:
It's definitely worth a shot for that price.
