Around that era,Leedy sold most of their drums ,undersized in what they called the "floating head" concept,so the head floated "floated" on the bearing edge,and the counter hoop didn't bind on the shell..
I'd bet the drum was sold as a 28" drum (which was pretty standard for that vintage),but actually measurers around 27 1/2 ".Nice kit,but priced a little too high.
Wish he would have pics of the cymbals. I rarely ever hear about those Zenjians, and what I do hear, it is a mix of truth and fiction. I got one here (12") and it sounds really good. MY daughter uses it for her little drumset. Be cool to find out info on it.