Air tank valve stop??

Hello AGN'ers!

I have a Tiger Shark from Brancato, it has a small leak, I assume through the brass, threaded valve stop with the Teflon (?) insert.
Brancato will NOT sell just that piece, they only sell the entire 'top end parts' as a single sale item at $90 + Shipping/Handling.
I tried the local dive shop and it seems that there valve stops are CLOSE, but will not thread into the female stem part. I believe that the valve assembly is made overseas, likely in Europe (?), so probably a metric thread, thus the dive shops here don't have them.
So the question is;
Does anyone know where to purchase just the brass threaded stop?
Looks like this....
Tank Stop 1.jpgTank Stop 2.jpgTank Stop 3.jpgTank Stop 4.jpgTank Stop 5.jpg


mike