Hello every one
First I thank you for all answers you wrote to help me for the resolution of the problem. The lack of these part was the reason why I had stop the work of restoration. With the new master cylindrer that I believed to be a good part I have restarted the job and even put off the cab from the frame.
Due to the small thickness of the pressure pipe, overboring the master cylinder would modify the small passage vertically into the fluid reservoir leading to a malfubction of the brake.
What ever the solution I have to change the bracket and build an other vertically bracket.
With these new bracket I could use a DODGE WC master cylinder (1' ¼) or the WAGNER MC9220 but these last seems to be no more available but I found Dorman M9220,
https://www.dormanproducts.com/p-29853-m9220.aspx
I have asked for availability