Lubrication on a Cambo

I have a 4x5 Cambo, model from the 70's, fairly simple, pre-Legend series, I think it is a 45N, or NX. It has the square rail and two risers for each standard. When moving the lens or back in and out, working from the back, the right knob does the moving (some kind of friction crank) and the left side (same kind of knob) does the locking and releasing. The left knobs are a bit stiff these days, and when tightening down can actually begin to move the position.
Should I lubricate the left side, with what kind of lubricant, and how do I do it?

I have the same machine...but have no such problem...but will wait to see the response for future requirements!

Consider a "build-up" of oxidents. Perhaps a strip clean is in order. There are lots of Cambos out there so a "solution" will be also.