Thanks gentlemen, I shot it for the first time today and it's absolutely amazing, functioned flawlessly, not to mention it easily out shoots my USP and Glock 34.
I will do some research with the authorities regarding the trommel mag but whatever happens I certainly won't be permanently modifying or damaging it.
And I'm in no rush to do anything with the holster, It's waited 98 years to be taken care of so I will exercise some patience
David, none of the mag's match the guns serial number but the stock is matching.
Cheers.