[Milsurplus] Knobs used in RBA/RBB/RBC receivers

[Mike T via Milsurplus]

Hello,

I have come to learn that the RBA/RBB/RBC series of receivers used RCA/Viz control knobs that were also used in many RCA consoles. It also seems that at least a few other companies have made copies of these knobs as well. My first question is how is one able to differentiate between a genuine RCA knob and a copy and my second question is where would be a good place to find a few RCA knobs?

Thank you,

- Mike