My Dad has the highbacks, same style upholstery in black...might even be the same seat without the provision for the headrest. If I were you I'd go ahead and make your own brackets, as the Scat brackets are still too high in the lowest (of three) setting.
My buddy and I both have the race'y lookin' 'rave' model seats, in velour and vinyl in our `77 Std's, the seats are a little low even in the highest of the available settings.