John,
the Bachmann 45-tonner is a scale representation of a ‘catalogue’ diesel locomotive. GE offered the locomotive with a choice of narrow-gauge or standard-gauge trucks, but the body was the same irrespective of choice of trucks. There was a recent rumour that Bachmann were going to release a Southern Pacific ‘Little Giant’ 3-foot gauge locomotive. However, given the criticism and poor consumer acceptance of the 45-tonner, I do not believe Bachmann will tread this path again.