I thought the Cub, Rascal and Chopper were the same re-badged mini's ?
yes and no, frame size and basic design stayed the same but lots of little things got updated, The bike listed is not a good example to look at because all the crap welded on, but the basics to tell what frame/model are mount or lack of at the back left downtube for long chainguard to attach to, engine mount plate design, rear wheel assy, and seat mount/s. I have seen one on here before that had forkplates like a Dart cycle too, I think that would have been the very first model around '64 I would guess, I dont have that in any of my literature, listing I have on them is 65-68 and they listed them as econocycle K-1 and K-2, and continental cub c-220 and k-220
that bike in the listing would be in the 1965-1967 range with what it has on it. They were offered as kit bikes less engine in that timeframe as well