In 1998, B2 #273 was taken out of service and remanufactured as one of the prototypes (the DC steeplecab – #719 – was the other) for the planned class M multisystem roadswitcher. Everything above the frame was removed and a multi-system drivetrain was built into a pair of low long hoods with a crocodile cabin suspended between the two original frames.

The Portland Shops engineering department decided not to use this design, but this unit is still in service on the P&W’s CSO lines.