I don't think it's a McCullough kart
But, if your interested in an interesting story
That's the same as the first kart I ever had
...the frame was broke on both sides right in front of the seat back
...the middle of the kart actually sat on the ground
...the sheet metal of the seat was all that was holding it together
But, it fired right up
The kid I got it off of demonstrated how to ride it.
He
...sat in it
...with his back against seat back & pushing against the steering wheel
...the bottom of the kart would raise up off the ground
...he pulled on a piece of shoe string, draped over his shoulder, to accelerate
...& he would relax pressure between the steering wheel & the seat back, letting the seat bottom drag the ground, for brakes
I didn't know how to weld back then, so I splinted it together with (2) cut off pieces of automotive tire irons (lug wrench)
I bandaged it together & beat on it for years
I remember riding it on a circular track, when running at full throttle, it would drift most of the way