Would the MASURCA system fit in with the timeline of the Jean Bart conversion? Or do you wish to convert JB prior to 1960ish?
1) 1958 project = conversion during 1959-1962/1963
2) The Masurca was
available only by 1965/1966 & in limited number (3 entire systems built by 1965/1972 for Suffren, Duquesne & Colbert, the 3rd Masurca system, initially intended for Jeanne d'Arc, finally ended onboard Colbert) and by 1966/1968 the Jean Bart hull/machinery began to be "increasingly worn-out (without a major overhaul)", so a Jean-Bart armed with Masurca was almost impossible (unless the French navy had completely rebuilt the ship, which is
extremely unlikely because during the 1960s-1970s, much of the money went to the french nuclear deterrence (SSBN))
3) Do not forget that by 1969/1972, the French navy, due to budget constraints (money for the SSBN fleet), has been forced to "reduce" the modernization of the Colbert cruiser...
On the web, you can find few Jean-Bart drawings with Masurca (& even Exocet MM-38 missiles & flight-deck aft for helico or LCM aft !!!).
These drawings are only AU/fan-art, not very serious, made by few french naval-enthusiast (often "heavily" inspired by US IOWA conversions projects...)