B.L.E: My 1966 Triumph 650 Bonneville had shifter on right, rear brake pedal on left. Of course it’s expected from people who drive on the “wrong” side of the road.
Mine was a '68 BSA 250 Starfire. Shifter on the right and brake on the left.
Right side shift was also the preferred layout for motorcycle dirt track oval racing because the left foot wears a steel soled skid shoe and is usually dragging on the ground.
That’s why the old Harley Sportsters had right side shifts. The Sportster engine was essentially the Harley K-750 engine converted to overhead valves and the old K-750 was used in AMA racing because of a rule that allowed 750 flathead engines to compete against 500 cc ohv engines.
I’ve driven a Vespa with a 4-speed shifter in the left hand grip.