I do not think the forward and reverse gears can be swapped into each other’s positions on the prop shaft. I have had a couple of these apart and seem to have noted differences in them that would prevent this. I’m sure someone will correct me if I’m wrong. The clutch dog can, however, be swapped end for end and if the reverse end of the clutch dog is in better condition sometimes that is enough to cure the problem. Granted, if the drive cogs on the gears are rounded enough, everything would have to be replaced. The entire gear set is listed in parts diagram on ME and on the microfiche card I have under one part number for the whole set of three gears. I know each gear has its own number, but I do not have that information at my disposal at the moment.
-Ben