>From http://www.classiclightweights.co.uk/
"In 1952 the centre pulls were introduced, engraved \u2018Dural Forge\u2019. These were a huge advance being efficient and easy to set up. The advantages over other types were many: a through g
The profile of these brakes is very distinctive and even a cursory glance at photos of Tour riders in the 50\u2019s and 60\u2019s will reveal many to be stopping on Mafacs. Once they became available in Britain in 1953 many club riders switched en masse. None of the competitors eg. GB, Weinmann or Universal marketed centre pulls until the late 1950\u2019s.
In the late 60\u2019s plastic bushings replaced the bronze ones and \u201cRacer\u201d replaced the stamping \u201cdural forge\u201d on the stirrups. In the early 1970s a longer-arm version was introduced, the Raid with a drop 60 to 85 mm with wheel guides built into the brake shoe fitting.
Dating - Any component with 'Securite' is pre-autumn 1947 - Early levers had solid blades - At the end of the 60\u2019s the stamping on stirrups altered from 'Dural Forge' to 'Racer'. - At the same time levers were stamped 'Mafac France'. Previously they had just been stamped 'Mafac' . - Early centre pulls had a tiny oil hole above the pivots only until 1953 - Parts with 'MAFAC' with full stops after each letter are the older versions - The later versions of the '2000' and 'Competition' had the month and date of manufacture stamped on the inside of the left arm (the earliest example I have seen is dated 1975). This was altered around 1978 to two letters one for year the other for month. "
Hope this helps. George Jones, Dallas, TX