I don't think the alphabetical boxes on the left were used, but I have seen some with punches, and some without. The ones that do, don't usually line up with anything printed on the left side of the card, but do with the number columns on the right. For my Super 88, it has the tractor serial number and engine serial number punched out, and my 1650 has just the specification number. I'd be willing to bet that one of those is the case with your card as well.

Many times the area on the left would be used to sign off, or would be stamped Cockshutt or Per Special Bill of Material. Check out the topic 1955 Heritage a few below this one in the list for an example.

There appear to be a few different arrangements of cards, and the codes would vary by model. By the time of the 50 series tractors, they were using 3 digit codes on the cards.