I recently purchased cams from S.S. for a 162mm lens for my top RF Crown Graphic . They appear to be new but not O.E.M. 1) the infinity position of the rack is changed compared to the original cam, is that normal? and 2) I can't tell any d ifference in a side-to-side comparison of the P11 and P12 cams? Should I be abl e to? They both seem to couple properly.