Good morning , had an enquiry from a guy who as a 63 RGS and as had a rear wheel rebuilt and now appears not to line up fit correctly between the rear s/wing arm. He thought it nshould have an offset of 7.5mm toward the drive side whereas it's come back without any ofset any one know what is the correct setup ? His info, also is a layford drum/sprocket 42-60846T a correct drum , many thanks for anyones help, best wishes BobH