The shoemaker who manufactured the PA’s was Edmond Bourdonneau (not Edouard as it is often mentioned).
Edmond Bourdonneau registered the trademark PA and the model of these rock shoes on July 22nd, 1963.
In the mid-sixties Pierre Allain and Edmond Bourdonneau stopped their collaboration and Richard-Pontvert (Galibier) started to market the redesigned red PA’s in 1966.
About at the same time, the blue PA’s became the EB Super Gratton.
I'm not sure, but Pierre Allain lived from 7 January 1904 to 19 December 2000. He looks like he could be between 30 and 50 years at the time. Maybe just after WW2 - around 1950? I will see if I can find anything.