Jules, I think the above story is very likely by and large right, all you have to do is transpose it a year or two back in time and it makes still sense (except that the doublecut ripper is already supposed to be in production). I take a look at my singlecut Ripper and it is an early seventies bass, not a mid seventies one. The fin, the shape, the ungainly size, everything to it. Who in the mid seventies would have gone back to the chrome pups and given up the weight-decreasing and production-easening routing as well as give up the string through concept so en vogue at the time? Plus: In 1974 the Ripper/Grabber family was selling like hot cakes, it was the most successful Gibson bass since the EB-0/-3 twins (and their various spin-offs) of a decade before. It was long scale, had a brighter sound and looked suitably unfenderish, what on earth would have possessed someone to then come up with an outsize singlecut alternative much heavier and more oldfashioned looking? And I don't believe for a moment that Greg Lake who by the mid-seventies played Alembic would have wasted a thought on the singlecut Ripper. They might have given him one in 1972/3 though.
So, yes, I think most of the details of the above story are correct and there is/was no ill will affiliated with getting the years wrong, the author himself says that the Gibson guy was not sure whether it was 1974. Not that it really matters. The singlecut Ripper is a nice piece of history, but I do not wonder for a second why it took the backseat to the doublecut version. Try lifting the thing!
And a picture (or a few) says more than a thousand words, to me that bass cries "early seventies (with still a good shot of sixties influence)":
On this last pic you see the bridge I put on to get a better action (it was basically unplayable when I got it and sold as such too, the trussrod wasn't frozen, but is hugely stubborn and the first generation three point was too high both as regards plate thickness and saddle height - btw another indication that this bass was an early seventies product, the mid seventies three points had already lower saddles), the bridge is a mix of a Blackbird basis (I have a Hipshot Supertone on my Blackbird) and two point white pastic saddles.