In 1966, the TdM shops re-engined two class DL3 locomotives with Alco 251-12 prime movers and Century-level electronics. (They’d planned to convert more, but the head offices were not yet confident in their ability to do more than maintenance on diesel locomotives.) #375 operated until 2024, when it was transferred to Musée ferrovaire de Parsons Vale, and #377 still operates (rebuilt as a RS-250 after a bad generator fire in 2002) on the Allegany County Railroad.