Originally Posted by Firewood:
The size could be somewhere between the AAR Switcher truck and maybe one of the Brill or Baldwin MCB trucks. Depending on the wheelbase, a supplier like Q-Car may have sideframes.
There is some resemblance to those Baldwin trucks. Unfortunately, Quentin stopped selling sideframes some time ago. You might be able to get him to build you a set of trucks with one powered with one of his drives and one dummy. Tends to run ~$135 +/- a bit depending on options and specifications; comes with a normal 3-6 month wait.