Those look exactly the same as the rear springs on my 53 1 ton. Best I can figure is that the bottom set is the standard spring for the 3600 and 3800 (3/4 and 1 ton), but the top set are the overload springs from a 5000 series. I think that the original owner of my truck special ordered these springs, for use hauling stuff on the farm. Partly I think it is factory because of the frame brackets, which aren't shown for any other series but the 5000 and 6000. I don't even see this listed as a RPO.
On the other hand, it makes the rear end hell for stout!
Tim

I am currently digging back in to a 1953 3800 (one ton) with a nine foot bed. I've owned it since 1979, and drove it until 1982 (or so). My wife got me involved in restoring it back in 2002, got the body removed and the frame redone, then things came up. Now I am retired and starting again. If anyone is interested I have photos on Imagur ( https://timwhiteblues.imgur.com/ ). I live way back in the woods in the Ozarks on 40 acres at the end of a 2 1/2 mile private road.

Tim