Help to ID rear axle

[oldman3]

My son bought a 52 AD a few months ago, we finally got it into the shop and took apart a few things. This rear axle was already in the truck setting on the leaf springs, with only the U-bolts and shocks holding it in place. I'm trying to find out which axle we have?
1st pic is showing center carrier with a small plate attached to carrier.
2nd pic is showing cover shape.
It appears at one time to have had brackets for coil springs, or arms, but not sure. They had been torched off. It did not have leaf spring pads for sure.
Rear axle is 60" wide, and on the passenger side tube the number FC 6K-204 is stamped. Any help is appreciated.