This is the front standard from my (obscure, no-name) 8x10 camera. The front standard fits on a rail, and lately it's been slipping while focusing or if the camera is angled up or down severely, You can see the cross section of standard on the rail -- two guides on top and a roller bearing on the bottom. In the past, I've made the mistake (I think) of lubing the bottom rail. Should I only be lubing the rails that have the guides? And if so, is there something I should add to restore friction to the bottom roller and guide?
The camera is old and some of the parts or worn. That could be another problem.
Thanks.