Pushing the way back memory from working at the Plymouth dealership, I think they originally moved very easily, as in without the throw out bearing in place, gravity would have pulled the lever down kind of easy. Being a cable operated lever, too much resistance would not have been good for long clutch life, or quick clutch release. I believe the shaft passing through the bell housing has a bushing in it, I suspect crud has built up around the bushing. I believe we used to hose the bushing area with carb or brake cleaner, then re-lube with spray silicone or white grease (been a long time).