I don't see why PL349 won't fit an earlier Gen1. The top of the pannier frame bolts to the 2 lugs on the side rails of the rack. The lower bracket bolts into the hole at the rear of your pillion footrests, you may have to loosen them temporarily to get everything lined up. Lastly there's a bracket that bolts the 2 pannier frames together. This passes behind the numberplate.
Whizz kid sitting pretty on his two wheeled stallion.