Odd choice. The M-18 57mm RCL I could understand, it was fielded at company level. The 75mm RCL is a bit less useful (for the French at least).
That said these are, as always, lovely sculpts and if they would sell the RCL separately it would find it's way into quite a few post war armies. I'd get one for my Soviet era Afghans and 1970s Africans.
Hopefully Paul some more Viet Minh infantry on the workbench.