LT&L #1 was the last of the LT&L’s fleet of passenger pacifics, and it only survived up until the PV&T merger because the president of the LT&L for the previous decade was a railfan.
With the exception of this locomotive, the LT&L’s class Ka engines were retired in 1953 after the the arrival of class P66-20-A diesels to take over the regular trains on the Québec/Montréal/Ottawa mainline. The central office was starting to think about keeping a museum fleet now that the writing was on the wall for steam, so #1 was assigned to the TdM, which used it for their last international passenger train (Montréal to Plattsburg, NY) up until the railroad was forcibly dieselised in 1962. It was kept for excursions and railfan charters after that, and was one of the first locomotives sent to the historical fleet in St-Constant, where it remains today, rotating into and out of excursion service with the occasional cameo on a freight.