the ok hand sign may have to do with the plumb line. Basically you hold a string like pendulum thing and that is why like tarot card and witch people pinch their fingers while doing the ok hand sign because its a masonic gesture. I was reading rituals trying to understand the keystone and in one of the rituals they instruct the canidate to hold his thumb and forfinger in the manner that they say to hold the plumb line with THE OTHER FINGERS OUTSTREACHED!