DEFINITELY a Kay. If you're right about the year, those pickups are a dead giveaway... by the late 60's, only Kay was using those "capped" DeArmonds... Harmony had since moved on to "mustaches," and Supro/National, by then, had either gone Japanese or had that faux-humbucker thing going on.
I've got a guitar identical to this, save for the body!! (You know the one... big and blocky, like a bloated, swollen Jazzmaster.)
I LOVE THIS. I MUST HAVE IT.... Its so damned hideous, yet like the doomed Kay "Solo King" from the early 60's, I find myself strangely drawn to it...
SOLO KING! I need one, too...