Carb to Manifold Boots installation.

I agree with warren. ALWAYS do the clear tube test. That's the only way you will KNOW what the fuel level is. Honestly now, this test is in the Kawasaki service manual for a reason: to eliminate guessing.

Thats the 2 million dollar question. Either set can be bought to spec easily enough. The newer ones are clean I dont know what the fitted ones are like. I suspect that you will end up using the best bits from both sets to make a really good set. As long as you dont mix moving parts, specifically the slides, between carb bodies, pretty much every thing else is interchangeable. So for instance if you feel the jets and float valves and seats from you old set are better than the new ones, but the bodies are better on the new set, just swop them over.
Just remember that whatever you do they will need setting up correctly, which is detailed in the service manual. Take time to read it and understand it and understand the effect of any adjustments you make. It details what to look for regarding potential faults and which items should be replaced if past there best and how to spot when they are.
Its midnight here now so Im off for the night?