Early-to-mid-'50s Radio Kings had clamshell strainers, so I don't know that I'd say those weren't real RKs. Back to my 'Gene Krupa' RK, it has 'Radio King' engraved in the hoop, but a clamshell strainer. I think it would be a stretch to argue that it wasn't a 'real' RK. That said, I'm in the market for a cloud badge RK with the 3-point strainer and brackets to remove all doubt. I really want a 8" x 14", which is extremely rare, so I'm prepared to be very, very patient. I will say that my clamshell RK sounds as good as any RK I've ever played, which is more important than semantics to me.
Stephen