M416 with a G.I tailgate?

[Bill, Idaho]

I saw one at our show a year ago. It was a standard M416, but it had a bunch of extra data tags, and was listed as a comm or generator variation. (definitely NOT an M762). It did have a few holes ( some round and some square) cut into the box, but with additional data tags above each one to advise what went where-as far as cables. But it had a nice, well built tailgate. I was impressed. It wasn't a Bubba job. Ya know, as I think about it, it even had a schematic data-tag on whatever it was installed inside the box.
The neat news....I found another one just like it, about 5 miles from my house. I was out taking a call out in the county and I drove right past it. I have driven past it a million times and never noticed it. For some reason this one time, it caught my eye. I am going to stop by there on my day off...the sheriff doesn't like us conducting personal business on his time.

Anybody have any more info on these?