What can anyone tell me about this unique 1956 one set only 6014 Chun King Boxcar? Everything I read says Bar-End trucks only. Mine clearly has AAR trucks and no signs of tampering. Its not even logical why someone would change the trucks...or fail to put the proper trucks and frame back on the body if changed. The frame and trucks are not the rare part. Any insight would be appreciated I am very interested in the variations, history, etc.