I have a 2x3 RH-10 roll holder and the winding lever is getting extremely difficult to operate even without any film loaded.Is there a way to lubricate it or is the problem something else?

Mike, I had the same problem. Check the winding key inside the holder---that's the little metal part that fits into the top of the take-up spool. Unscrew this clockwise---it's a left-hand thread---and remove the brass washer that you'll find underneath the key. It performs no essential function, except to jam up the works as you have noted. Replace key; you may not need any oil, but if you do, any plastic compatible light oil should work. I use Labelle #107 or #108 from the model railroad hobby shop.