I have an (early) 81 righty Ripper, my understanding was that they were built until 81 with a few possibly creeping out still in 82, there were Grabbers and G-3s still being built as late as late 1982 (though not many) when Gibson was already pushing the Victory as the follow-up to RDs (which had already been intended to replace the Ripper as the "variable bass" for the more discerning player, but failed to generate the necessary sales) and Rippers. They had modifications such as ebony boards or three piece necks to the previous maple board and one-piece-neck Grabbers and G-3s.
That doesn't make your model any less rare, I've never laid eyes on a leftie Rippie before nor am I aware of a lefty Ripper-playing name musician (except you of course!) who might have had the luck that Gibson would have built him one.