1960 RCA CTC-10B Roundie

[Radiotronman]

I just picked up a 1960 RCA CTC-10B roundie last weekend. It's in great cosmetic condition and the 21CYP22 tests like brand new! I can't find this model on the 1960 rca ctc-10 lineup at all. Cosmetically, it has the knobs and badges of a ctc-9, but then has the holographic color logo like the ctc-11. I haven't seen too many ctc-10 roundies, were production numbers on these sets lower than the other ctc's?