Boss have recently introduced a side lever over and under which they sell with a pair of interchangeable side levers so that the purchaser’s child or grandchild can decide which suits them best.

Slightly off topic, at a Christie’s auction view many years ago I picked up an English SXS gun that had been built as a true left hander with the top lever rotated clockwise to open the gun. I nearly dislocated my thumb trying to open it the usual way before the penny dropped.