The RL-83 Blindicide was produced by Mecar SA of Belgium and was an improved derivative of what man-portable recoilless anti-tank rocket launcher weapon, widely fielded by the United States Army?
RL-83 Blindicide:  It was produced by Mecar SA of Belgium and was an improved derivative of the M20A1 Bazooka. Bazooka: Bazooka is the common name for a man-portable recoilless anti-tank rocket launcher weapon, widely fielded by the United States Army.
Bazooka