Never seen one like that, but if your FCR has the open/close dual-cable setup like mine, you could run a short cable from the "close" side of the first carb to the "open" side of the second one. That's sort of like the early BMW oil head cable setup. Seems a bit easier than dealing with two independent cables adjustment-wise, just back out the second cable until it's barely slack when the first carb is idling.
If this is what you were planning to do anyway, don't mind me. Carry on.