Was the M8 AGS also known as the Stingray? I remember the Stingray was basically a Sheridan hull with a redesigned turret mounting a 105mm main gun (not the Brit L7). It disappeared from the Army's radar screen in the early 90s, but the Thai Army bought it. I remember thinking it wouldn't be a bad vehicle for us Scouts, to work as a team with our Brads.
Scouts Out! Cavalry Ho!
It had the same 105mm main gun as the M60 and M1 Slick, but was equipped with an autoloader which left it with a 3-man crew. Like the Sheridan it was designed to be transportable in a C-130. One of the neat features I thought would make it especially for an assymetric/OOTW type operation is that it had three bolt on armor "suites" which allowed the level of armor protection to be upgraded in theater according to the conditions on the ground.
I always had a soft spot for the Sheridan and when I played NG for a while, there was a Sheridan TC in the same outfit. He was one wild dude but a good guy.
This one was sitting at an aviation museum in Charlotte. I think it is just a sealed up body.
http://tysonneil.smugmug.com/Military/M551-Sheridan-Tank/12993910_Xo3fx#940273551_TeUKK
I have right click/save and linking disabled, hence the full page URL.