Overlay:  World Series Major League Baseball (Right) (Blue)Mattel overlay Item Number: 4537-4289-G1 Copyrights:  Mattel Inc.1982.  Printed in U.S.A.  Description:  The overlays for World Series Baseball are not actually different versions of the same overlay. There are actually two overlays for the game. One (above) is for the right hand controller. It has a blue header & is noted as (right) in the text. It represents the National league. No variant is known to exist.

Overlay:  World Series Major League Baseball (Left) (Red)Mattel overlay Item Number: 4537-4299-G1 Copyrights:  Mattel Inc.1982.  Printed in U.S.A.  Description:  The left overlay for this game has a red header. It is to be used in the left hand controller of the Intellivision system. This overlay represents the American league. An interesting note... to seperate the game item numbers, the left hand overlay ends in 4299, not the usual 4289!