Unusual trailer?

I was at the show in Idaho, and saw a rather strange M416 variant. It was an M416, (according to the data-tag,tub, fenders, etc). It also had a data tag on the front passenger side saying "AN/MRC-111" and had a schematic of a rather elaboarte radio setup of some sort. There were 1/2 inch holes drilled into the top in a couple of places, with a "ground" tag riveted nearby. It had a tailgate cut into the tub, and was done pretty nicely. There were plates welded up both rear corners, where the tail-lights are. The GI lights were gone, with cheesey Walmart lights installed. I did notice though that there was a hole cut into the right plate that would have provided clearance for the blackout light that should have been in place.
My web-fu, including google-fu didn't show any info. Butcher job or ubber rare variant?

Was a government modification for radio sets... I had one once, not to many around... The AN/MRC-111 should pop up in some radio guru's mind...

My Google gave me a link to a radio list and another link to AN/MRC-111 which indicated all the info you need for this trailer... It was a radio terminal set and consisted of a couple radios and a gen set mounted in the trailer...and called a SET....not a trailer... However as you know, it started out life as a M416 and was purpose built afterward.. Not unlike the cable splicing sets and the smoke generator sets