I think K1 Vin #s started around 1200001. The lower the # the more likely it has early version Z50 parts...i.e. rare parts. Be careful with every part, including original bolts, etc until you know which ones can/should be replaced.
I can see that you have a odd carburetor on that bike...not the original.
More pics please. Maybe start a thread of your own so we can see your progress.
Welcome to lilHonda.