I only briefly considered this. Don't know if being completely stock makes it more valuable or not. Mine may be original to the car but the spring pad welds don't look original, look bigger and sloppier compared to the rear under my dad's firebird. Front right corner on the base of the left pad, right where the bolt goes through was purposely cut out for some reason as well. Figured this would discourage interest.
It does have new Moser axles w/ 1/2" studs, new eaton posi, new richmond 3.08 gears, bearings etc. aluminum TA performance cover. All less than 100 miles on it. I would take the 13" disc brake kit off but still have the original drums. value estimates?
I've got ~ 250(axels) + 450 (posi) + 150 (cover) + 250 (gears and install kit) is over $1100 (plus tax, shipping) bucks worth of practically new equipment.