THank you both. Yes, It was a GI Joe Rolling Thunder. I call it an AT-TT, for lack of a better term.
Aside from two-tone paint work, I basically:
removed the rear turret and replaced it with a soffit vent
removed the entire inner frame with ICBMs, replaced it with seatas from a GI Joe APC and the track for the scout car between the two ramps
cut out and hinged the rear deck into a gantry
wedged on of the rear tire, because this particular one had a cracked axle