Gatecrasher, it's a 1979, so why wouldn't it have a '79 oil tank and '79 handlebar controls?
It looks like it does have a 76-80 oil tank and 78-80 controls.
You can tell for sure what year the frame and engine are by the serial #'s but it isn't that important unless you are restoring one to absolute factory originality. Even then there are only a very small group of MT1/KV75 freaks who would even care.
I have both all-original and customized bikes. Your bike is definitely sweet but it is not 100% stock other than the color. It has some other custom features.
The z50 fuel petcock is a nice revision, especially since the Kawasaki ones are expensive and hard to come by. I like the z50 petcocks because they have the "reserve" setting too where the original didn't.
Since over ten times more z50s were produced than MT1/KV75s, there are a lot more reproduction parts available for them. It's nice that several are interchangeable with the Kawasakis like the gear shifter and kick starter levers too. You can also fit the aftermarket forks and rear swingarms to the KV75. Some parts are unique to the Kawasaki though like the rear sprockets. If you convert to the Honda wheels you can use the more readily-available Honda rear sprockets but I prefer to keep the Kawasaki wheels.
The reason I'm into these bikes is I had one as a kid in the 70s. It was a 1971 MT1 "Parnelli Jones" and I rode it hard every day. I used to blow every cent I had and then some keeping it maintained and running. The three parts I used to have to replace more often than anything else were:
- The sprockets and chain
- The throttle cable
- The foot peg rubbers
There was other stuff too but those were the main three. I blew the engine twice and had it bored for new pistons. These bikes are a great learning tool for kids to gain mechanical ability.
The shocks you have on the back are a nice upgrade. The original Kawasaki shocks were pretty-weak and definitely inadequate for an adult rider. My springs were broke on mine back in the 70s.
I have the same aftermarket shocks that you are using on all my bikes that I ride. I have a total show bike that I don't ride that still has the originals on it.
The rear sprockets for these bikes were selling for over $100 on eBay for an NOS one (if you could find one). They are unique to the Kawasaki. So I eventually got tired of it and decided to have them manufactured myself. You have one your bike.