Lincoln Service Parts 1 › Lincoln Electric 9SM21503 CONTROL BOX ASSEMBLY M21503 Lincoln Electric 9SM21503 CONTROL BOX ASSEMBLY M21503 Sale Price: $622.75 Original Price: $716.16 CONTROL BOX ASSEMBLY PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1 Add To Cart Added! CONTROL BOX ASSEMBLY PURCHASE PRICE SHOWN IS FOR A QUANTITY OF 1