From the Service Manual (1919): "... turn each of the expander nuts in the same direction as the hands of a clock, right to left, until they lightly touch the clip, then give them a half turn on the opposite direction."
From the Repair Manual 1918-1924: "To adjust the expanders, turn each of the expander nuts from right to left until a thickness gauge about .005 of an inch in thickness can be placed between the nut and clip".
I think Mike 1922 is right, you don't need a lot of oil. In the end of 2006, the same year as I had bought my 1922, the leather split in parts and fell off. When I installed a new leather I used a paintbrush to put neats foot oil on the outer surface, quite generous but only once. The clutch worked fine, after 50-100 miles I adjusted the expanders two or three times.
One year later, when I made a major ovorhaul of the engine, I checked the leather. I looked fine, so I just put a little neats foot oil on the surface. After one or two adjustments of the expanders the clutch has been working fine during 18 000 miles driving. No grabbing, no slipping. When I checed the clutch I also noticed traces of motor oil the inside of the cone, and also some on the leather. I guess some motor oil that lubricates the balls for the "Clutch Spring Tensinon Rod" finds a way to the cone, but I don't know wich way.
