Luke, your reference photo is one I put up many years ago from the original seat covers I replaced in the then about 43k mile '51 in my tag line. For reference I made a series of about 20 images showing the seat in original condition as I removed and then replaced the covers and padding. I'll check, the original card "may" be in a dark corner of the shop. If so, you're welcome to it. Not sure if it'd be worth the effort though since it was a tad fragile 10 years ago.
ps, you’ll notice pins securing the card to the seat back, I just added pictures of those. RonR