Can a bachmann 2-10-2 be turned into a baltimore and ohio s-1a big six?
There's a good thread on this exact discussion under the General category. Short answer - You really need a Rivarossi loco for the boiler/cab assembly and the drivers in the Bachmann model are too small for an S-1 (58" vs. 64", as I recall). The driver size is OK for the earlier Class S. the IHC 2-10-2 is a better fit.