I'am just arriving on your site and what a surprise ! you are speaking about of the Potez75 ! This ugly bird was a french prototype, may be a "COIN" ancestor, developped it seems for algerian war in mid '50. His name come from the famous french artilery 75 mle 1897, wich was the gun of victory in 1918.
The 3 views drawing come from "le fanatique de l'aviation", the better and older french review over war aircraft.