It is no wonder that the LP Sig flopped in the mid seventies when it came out - it looked hopelessly outdated at the time, designed by an old man (as Lester already was back then). No one in his right mind wanted to play a hollowbody back then, be it this, a Fender Coronado, a Ric 4005 or any of the Gretsches. Hollowbodies were identified with feedback, muffled highs, boomy bass etc and while the LP Sig didn't sound like that at all it got binned because it looked the part.
Hollowbody basses - to this day a niche - did not really reach cult factor before the later nineties. Even the early nineties EB-650 and EB-750 came too early for that craze and had consequently poor sales.