1980 KZ750G fuel petcock HELP!

Can anyone tell me about this valve? I need a rebuild kit due to leaking when I turn it on/off. I believe it’s only the rubber bushing (has four holes?) that’s  damaged. It’s on a 1980 KZ750G and it’s a dual outlet.

Howdy. I tried the diagrams at Partzilla but yours doesn't seem the same & I don't know if your fuel valve is stock or from another model or what. The ALFA markings could indicate that it's an aftermarket petcock from back in the day. ??? 
www.partzilla.com/catalog/kawasaki/motor...i-kz750-g1/fuel-tank

In case there aren't any repair parts.  Z1Enterprises.com lists a number of fuel valves, but you'd have to figure out which one will fit. 
From some other topics the fuel tank bung is probably 22mm w NPT threads (13/16 on a Harley), but you'd have to verify that.  
Pingel brand are kind of pricy but should be high quality. cheap chinese on EB are known to fail or break.

That's not a stock petcock, the reducer is the give-away

What did the stock petcock look like?

wrote:

What did the stock petcock look like?
 

If you click the link that martin_csr posted, you will see an exploded view of the factory valve.