I built my own years ago.
Trackmaster built a frame for me with a kickstand. I added the rest.
XS-650 motor bored to 750 cc. Big valves, cam, carbs etc. The motor was a clone of what was being raced on the dirt tracks at that time.
The State of Colorado issued a vin number and a title.
I've NEVER had a bike that vibrated like that thing. It was a blast to ride on dirt roads.
It was a quick handling bike on tight paved roads, but the frame and the forks flexed quite a bit.
Sorry for the poor quality pic. I had to scan it from an old picture.