I don't think I'm an expert, but I do know a few things.
As far as I know, there were some .41JMP barrels produced, but I have no idea how many. I don't know if there were any complete pistols packaged and sold.
Will a 9mm WinMag (AMT AutoMag III or LAR Grizzly) take .30 Mauser ammo?
no. Not even remotely the same round.
Don't know if Wildey ever sold any .30s. Wasn't a catalogue item I ever saw.