The MAFAC "dural forge" (racer) brake was introduced in the end of the 40s or beginning of the 50s and built until the end of the 60s.
If I am not mistaken, the calipers are Zeus Alpha units. Pretty close copies of the Mafac. My Zeus ran the Super Alpha side pull calipers. As usual, the Super Alpha calipers seem to be a copy of another brand. As I recall, Zeus had a habit of copying the work of others, including Campagnolo.
This, in itself,
might suggest a slightly earlier vintage.