I was watching this documentary on Amazon Prime called Black Hawk Down.  It seems pretty good.  Actually I learned a few things I didn't know because I didn't read the book.  

Anyways...  They pictured Ruiz up close with his rifle and he's got I think an aimpoint 7000 or 2000 on top of his 20" A2.    

I've never seen a 20" A2 with an Aimpoint on top of it in the service.  I've seen it on Carbines, I've seen it on A1s (Navy Seal pics in the 80's on the carrier, you probably know those), but never on an A2.

It's a good watch.  I see mostly 20" A2's in the pics.  But I did fall asleep one time watching it, so I might've missed something.  

I saw A2s with Aimpoints on them several years ago on a range at Fort Riley. Pretty sure it was a Reserve unit that shot next to us that day.

Somewhere around here there is a Blackhawk Down pic thread.

There are some really interesting early 1990s'  rifle/ optic combinations in it.

For some reason I don't remember one with an aimpoint on top.  Maybe I'm not remembering properly.