(I posted this on Graflex.org as well, if I get a solution on one I'll update the other)

I have recently taken possession of a Series D in which the left-side focusing gear is off to the side of the rail towards the body such that when the focusing knob is turned only the right-side engages. I have tried easing the stubborn piece back into place but it resists all efforts. Before resorting to percussive maintenance I thought I would see if anyone had less persuasive advice.