Standard M73 is the evolution of the Standard M64 traffic lights. The "M" corresponds to Micheline, first name of the granddaughter of the founder André Garbarini, and leader of the company in the 1960s.
Very resistant because made of steel, M73 traffic lights were very common in the 1970s/1980s. The SNCF has ordered many copies for level crossings and pedestrian crossings in the middle of tracks in stations.
The Standard M73 were installed with the same repeaters and pedestrian signals as the Standard M68 range. They were still in the catalog in 2011.