The complete rearend. 4.5 bolt pattern. Turns freely.
Rotors look good. 9.25 not 8.25. Unknown ratio.
Whatever comes with 75 imperial.?
Somebody correct me if I'm wrong,it's a direct bolt into earlier Cs
There were still options for the rear gear and SureGrip, it would be in both yours and the potential buyer's best interest to figure that out. Turn the yoke and see if both sides turn the same direction, count the turns for a quick estimate of gearing (yoke vs flange)... interested parties will figure everything else out from there.
I know of one that was transplanted into a 71 Satellite without modification, so yes, there would be a lot of places it could be fit. Unfortunately, only nut jobs tend to go for these. Either Formal owners saving an Imperial, or folks too stubborn to find something more "bolt on" friendly from the aftermarket.
In any case, your price isn't out of line, but you really MUST get rotor measurements to justify the sale for someone who is knowledgeable. The ability to cut them clean is always in question with rusty rotors, and something I would never recommend if replacements were available. The real value is in the rotors here, but a SG rear or a deeper ratio might be a hot item for the right C Body owner. To my knowledge, the axles and housing are the same as drum cars. Calipers and pads are easily sourced, but everything else is unique. Caliper mounts, the park brake pieces and the dust shield/backing plate are tough finds for those who might need them.
FWIW, there is somebody who is selling or has sold a set of these brakes for twice your price, and his didn't have an rear end, just the brake pieces. Personally, I would steer folks to this if you had rotor measurements. If they were on this side of the country, I might have even come checked them out myself. There is also a set of take off rotors that has sat on EB for $600 forever... so nobody seems to be that desperate.
p.s. your inbox is full... FWIW, if you are selling in volume, you might consider the gold membership and its ginormous inbox storage.