1967 12 bolt with traction bar appropriation

[Zman1969]

In general a good used 12 bolt that is not posi is worth 800-1100$ maybe more to someone with "the" car that needs that rear end
this one appears to have a perch that was re-welded and a 69 and later yoke on it but looks in fairly good shape any info on whats inside of it? being that has slicks on it perhaps the gears have been changed an posi or locker added?