ID this truck?

It's a big REO 10 wheeler. It looks like an M35 to me, except for the bed detail there. There are some pictures of M35 based tanker trucks with that cut out detail.

My knowledge of trucks ends at this point...

Is that Corporal Cisneros?

It looks to me like an International Harvester M41 5 ton.  

It is not an M-41 as the M-41 doesn't have duals.  The mystery truck has duals.  It is an M-54 if it has a 14" bed, or M-55 with a 20' bed.  Wiki has a photo of a m-54 with the same bed.  Must be an early type bed.

The bed does not look long enough to be a M55. The M41 looks close... except for the rear dual tires... an M54 with a cut out bed?

I believe that the trailer being towed is either the radar or battery fire control van. I’d have to peek at their organization set up again to be sure.

GM, that is indeed PFC Cisneros, on the right front, with the dark hair and his cap tilted back.

I still vote M41.  The original truck looks to have super singles to me, just w/uni-directional tread.  Here is another.

Here is an M41 w/dual rear wheels as well.

Well, if there is one M41 with rear duals, most likely there were more. Now to find a 1/35 kit...

The initial takeaway here is that the trucks were built to standard plans.

I'n looking at basic alignment details, there actually were not too many aux. trucks in the 50's that the Army bought.

Makes me want to buy another M38 and not muck it up.