Please help ID this rear end

[glock35ipsc]

This was the rear end that was in my Dad's 72 when he bought it. It was obvious that it was not the correct rear, so he located one and we got it installed. Now we need to get rid of this one, but have no idea what kind it is. I will pull the cover sometime to see what the gear ratio is, and what type of carrier it has.

The only stamping I can find on the axle tubes is K J N G, it's on the right (pass) tube, and there is no tag on the diff cover.

But before I can sell it, I need to figure out what it is, and what it might be worth. Any help??