I also own a ROK B12H & I have a Gates CB77 on the way to me. Both are considered up at the top of the line for their respected companies.
The Gates has a strong following and so does the ROK. I have had numerous people tell me that the CB77(12") & CB500(16") when properly restored & plinthed are without a doubt untouchable in the Broadcast area.
If you have 2 ROK B12h's, why not just sell one of them? Keep the other & keep the CB77. Thats what I would do anyway. You will be one happy camper by owning both of them.
Use the money from the one you sell to upgrade the others. Without a tonearm you could definitely get at least $300 & probably more for it. With a tonearm, the price will only go up. Of course that is dependent on what model the tonearm is.
What kind of tonearms do you have on them?
Could you posts some pics of them?
Just my 2 cents,