Jon makes excellent buildcards, high quality on correct card stock. Years ago I actually shared a few examples of cards with him, some dealer info, and other notes/observations and he sent me 2 updated cards no charge.
The build card is more accurate and complete, my understanding is it was used to make the fender tag and buildsheet. For example, my fender tag has a scheduled shipping date, which is also on the buildcard, but the buildcard also has the actual shipping date which was earlier, it appears on the one above it shipped on the exact date it was scheduled.
They are easy to decode, all the punches represent the last digit of the 3 digit code. If there is more than 1 option for that section there will be more than 1 punch. It looks like the above card has 421, 428, and 429. Also, depending on the year, any letters will be represented by a punched number and a punched letter, or 2 punched numbers like the one above, UU1 is represented by 4 and 0 in 26_ and 27_.
Later years have a couple rows of letters above the zeros so there would be punches in odd places on those.
The 3 digit codes correspond to where and if it ends up on the fender tag and buildsheet.
I went overboard with this stuff a few years ago, created buildcards, buildsheets, fender tags, and an easy way to decode all in Excel.