If the frame is offset at teh steering hoop attach point it may be a Bug Scarab. They were inroduced around 68/69 and used primarily for enduros. The ones I saw had a bolt on steering hoop and maybe the seat too. It's been too long since I saw one. I was allowed to test drive one of the prototypes at Willow Springs a lifetime ago.. It was a follow on kart to the ESII Scorpion.
Thanks Michael. That is where it offsets and since it has side mounted tanks that makes sense. It also has front brakes. I have a better shot of the frame from the top that shows the offset. I'll try and post it later tonight.