Hello from Virginia

Bolt spacing on the ZRX and KZ1000 seem to be the same. Hmmmmm.

If it helps on those carb drain screws. They had two different kinds, early 92066-1045, late 92066-1064. Seems there's an abundance of the later 1064's but early 1045's (the type on the bottom, not tapered) seems NLA. But no problem, looks to be the same as used on the Suzuki GS1100 and Yamaha XS1100..i believe. Might verify diameter and pitch. They were All Mikuni so hopes would be high.      

Is the bottom picture a pilot air screw?

Kinda resembles one but No, its the bowl drain screw sans oring. Sans O-ring. Betting it's the same as used on the BS34's. 

OK, it looked a lot like the (16014-012) air screw on my Z1, after looking both up I see the difference