1979 kv75 carb

I have a Kawasaki kv75 with carb issues. I have a missing part in carb and also a part or two that needs to be replaced. I have found that’s parts are pretty pricey. Was thinking of just a new carb, but found that they are so many different ones, that says will work with this bike. Has anyone got a new carb from places like eBay, that is an exact replacement and nothing needs to change? Thanks for any help u can give me...