I've only seen the lifting bars on USMC trucks, though I have a friend far more knowedgable than me who claims they were standard equipment for the Army also. I've only seen them on two USMC trucks (both surplussed) one in use at an airport here in AZ, and mine.
I bought a derlict, engine stripped, 1953 REO, M35 gasser, it was USMC, and it while the winch was long gone, they left the winch extensions and pto, and those lifting brackets. A couple years later I bought another 1953 REO, in CA, that had been rebuilt to A2 standards (C turbo) but still had it's original 1953 data plate! Must have been converted at the user/unit level I guess,.......beats me.
The truck is even undercoated which made me think possibly it was a USMC truck before it became a CANG truck. /but I've only found ARMY and USAF paint, I don't think it was ever a Marine truck.......but it will be when I get done with it!
I sold the USMC parts truck, but not before swapping out all the winch stuff, and the lifting bars, all that stuff, including the USMC hood is now on my '53, A2.
If you notice in the picture in this thread on page 2 I think, you'll notice that the "C" shaped round stock that supports the lifting bar has welded on supports at each side. This was a USMC only modification, and if your using the lift bars, to represent a USMC truck you will need to cut some of these out, and weld them in place to be correct, I just got mine cut out, but have so many projects I haven't welded them to the truck yet.
The USMC parts truck had the welded on braces, but I had no way to cut them off at the time, so they went with the truck.
Also, if you are going to use the lift bars, in the Marines they would have been used in conjunction with the "paperclips" on the front bumper. So I'm going to have to get a set of those made up, and welded to the front bumper.
As a side note, I have been told that these were used to hoist the truck aboard older style cargo ships, but now that most ships are of the drive on/off design these lifting attachments are no longer required, so that's why you only see them on older USMC vehicles, or see the "paperclips" cut off of most more "modern" USMC trucks.
I was told by several people not to go off roading with the lifting bars attached, but I have had mine on for over 4 years, and have had the truck in some EXTREME situations on abandon mine roads that were so steep the truck literally slid down the hills as the roads were so steep (talk about pucker factor!), and had to climb over major boulders that had slid onto the roads, and have never had a issue with those bars damaging the trucke