The fact that it was pretty complicated, difficult and expensive to aquire or transport modern Soviet military equipment during the height of the Cold War to the US, led to some interesting modified US vehicles for the OPFOR (Opposing Forces) role.
One example of such vehicles were a small number of M109 Self Propelled Howitzers, which were modified in such a way that they looked (at least a bit) like the Soviet ZSU-23-4 "Shilka" Self Propelled Air Defense System. For this modification, the Army used the chassis of the M109, removed the gun barrel and replaced it with a mock quad cannon and installed a mock radar antenna on top of the turret of the M109. Pretty cheap and pretty effective. The photos were made in 1977 at Fort Ord, Central California during a exercise, which trained the cooperation of air and ground assets of the Army and Air Force.
Its not like that US allies never captured any "real" intact "Shilkas". Israel for example captured dozens of them during the Yom Kippur War in October 1973. And US agencies were pretty aware of the secrets of this Soviet air defense system. But beside the fact that Israel used some of them as part of their Armed Forces, why to spend much money into transport etc. to just have a "real" vehicle for the OPFOR role. That made no sense, so the US preferred solutions like with the modified M109s, or modified M551 "Sheridan" which were also "disguised" as "Shilkas".













