[1] It was decided that the new Metro would use a similar rubber-tired train design as used on the Paris Métro – instead of steel ones as used on the Toronto subway.

[4] However high tariffs on manufacturers from France (22.5%) and Britain (7%) meant that only two bids were received in June 1963, both from Canadian firms.

[5][6] The cheapest bid was from Montreal Locomotive Works (MLW), who had built the M series trains for the Toronto subway.

[5] However, aircraft and shipbuilder Canadian Vickers had the support of the French company CIMT-Lorraine which helped to design the rubber-tired system used in Paris.

Between 1991 and 1993, all in-service MR-63 cars underwent major refurbishment by AMF Technotransport at the Canadian National Pointe-Saint-Charles workshops.

[18] Further upgrades and improvements included solid-state door interlocks in 2003, modern ergonomic driver cabs with new digital dashboards, and automatic station announcements in 2005 (voiced by Michèle Deslauriers).

[23] The last original train was decorated with information about the cars and featured copies of posters from 1966 from its early operation.

[30] The MR-63 was identified with grey interiors, four ventilation hoods protruding over the roof of each car, two 113 kW (152 hp) 360-V series traction motors that make a whining noise, and round cab headlights.

In the early 1970s, two separate three-car trainsets had their original traction systems replaced with two chopper prototype traction systems, one manufactured by Hitachi (fitted onto elements 10, 11 and 12), and another manufactured by the Canron company based on a Jeumont original design (fitted onto elements 40, 41 and 42).

[19] In later years, obsolete components and parts availability meant the trains gradually became less reliable, and ride quality deteriorated as suspension systems and rubber spring packs hardened with age.

[19] By the time of their withdrawal in 2018, Montreal's rolling stock were among the oldest still in use on any metro system in the world, at 52 years old.