In this 1963 view at Logan Square, we see cars in the 6551-6600 series at left, in fresh paint, next to others from the 6601-6670 series at right in their original paint. (George Trapp Photo)

In this 1963 view at Logan Square, we see cars in the 6551-6600 series at left, in fresh paint, next to others from the 6601-6670 series at right in their original paint. (George Trapp Photo)