I don't know the history, it came with a large parts haul I picked up recently.
I am not sure what this is for, it could be Dana 30 or Dana 35 from the research/pictures I see.
I believe it to be a Spartan locker, but again, I am not 100% sure.
The pieces look more like Dana 35, but I also see that the cross pin/shaft is not present in what I bought.
These go for $500+
If you know what is missing and can use it, it is a good deal.
It comes with a rebuild kit as well from what I see in the padded package.