Your right the rear springs don't appear to be correct. Not sure if there was a bottom coil spring cup or did the coil spring just sit on the back of the spring pack from sheer force? The springs don't appear to be any different from the fronts. They appear to be "original" but probably not "factory". I am not really sure what I have found. The jeep was painted in either a type of chrome yellow or a highway yellow inside and out including the underside. and even the steering wheel. Everything was yellow at some point and appears to have been applied directly over the OD.
My latest theory is that the WV DOT stuff may have been just a story to explain the yellow paint as an aid in selling the jeep to the person I bought it from. The jeep appears to have had only a few civilian owners from what I can tell as the title was last processed in 1980. I am thinking the jeep may have been a "Follow Me" jeep or an airport tug of some kind with a heavy radio or tool kit. There looks to have once been an antennae mount of some kind on the hard top. I found some stenciling on the hard top above the windshield that may eventually help in figuring out what kind of jeep it was...
Lots of investigating on this jeep still to do... There are pictures of the jeep on the www.willysmjeep.coms
website under M38 Barn Find.