The "conversion", while possible, might be more trouble than it was worth. Then there is the safety consideration too.
Fiocci used to import Berdan Primers. The question is, which size would you need. I think that Berdam primers were somewhat "non-standard", though I could be wrong.
9 x 18 Makarov, boxer primed brass is readily available from Starline. One used to see Israeli ball ammunition in 8 MM Mauser. It was Boxer Primed, and non-corrosive. Might still be some around. Also, Federal is
loading Makarov ammunition, Boxer primed, in their American Eagle line