Thanks to Mick, we added a 1990 SC Mustang to the Project -
http://www.specialservicemustang.net...info184671.htm
I started checking out the other SSPs in that batch and found an interesting one -
http://www.specialservicemustang.net...info184669.htm
Note that the seller claimed without realizing it that one tag reads 22-0078 and the other one reads 22-0079. I figured it was a typo in the seller's listing. Well, there's another SC car from that batch which has different DSO numbers on its tags -
http://www.specialservicemustang.net...info184662.htm
The VIN label shows the DSO to be #22-0079, but the Buck Tags have two differing DSO numbers (#22-0078 and #22-0079). If you go back to the first link in this post, it looks like its two tags may be the same way. Does anybody remember ever seeing a typo like that on the Buck Tags?