Phillipe- Doesn’t that kind of pump interfere with the shift rods? Jose Franssen sells a low-profile pump that will not interfere. I think the glass bowl type is more suited for a 15/6, but if it works on an 11, that’s good. At Arras in 2009, I bought a glass bowl type for a friend with an 11B and the rods rubbed against the pump. I have this one on my 49 BL and it’s given me no problems and it’s a lot cheaper than the glass bowl type:
https://www.citroen-traction-avant.com/en/shop/article/595=!822-V/Fuel_pump_right-angle_new