That's a universal problem when trying to get these old parts & accessories remade. They were made by very talented men & women, so can be made again, but at a price, & that price is often so high as to make the idea non-viable. I hit exactly the same barrier when trying to get someone to make, say, Aldis Purdey mounts at an affordable price. I have mentioned on here before that what is needed is a retired Rolls Royce (or equivalent) toolmaker with an interest in model engineering so that he has all the kit in his garage or garden shed, & a wife with a love of expensive foreign holidays, or designer handbags, or some such, so that he is keen to earn a little extra money.........that was precisely the relationship I was fortunate enough to have with the late Graham Smith......an eccentric of the old school, but a genius with a lathe, milling machine, shaper, pantograph..........you name a machine & he could make it purr......