Your bike is a Mk2 frame and not the same as the Mk1 in the ad. Notice the difference in the seatstays/dropout. Most of the components should be similar, but I believe there are some other differences.
It looks like a 1972 bike, a project for sure, I don’t wanna sound like a complete vulture, but if you do ever wanna part with it please do get in touch
The struggle was real back in the late 60's early 70's. I can see the designers smoking fat cigars while designing this one. "Lets put not one but two shifters that are really slung low in the center of a kids bike; so the kid has to take his attention off the road and look down to shift the gears." LOL I would rather temp life and look cool instead of what these so called wennie bikes are today. Love it awesome bike!!