Here's what I did, take a peice of 5/16 (8mm) alloy plate, shape it to suit the base of the new reg. drill to suit the holes in the dynamo clamp, you have a choice here- either countersink the holes so the fixing screws sit flush with the top surface, or using a suitable milling cutter so the allen bolts sit flush . Align the reg to the mountin adaptor, drill + tap according, bolt=on, rewire according, Roy.