Yeah, I don't doubt that my truck is a base model C/10. Especially with the "long list" of options on the SPID.
My assumption is that a particular plant, St Luis in my case, was putting Custom glove box doors on C/10 pickups. That's why I was wondering where Becker67's C/10 was built. My truck has had one exterior repaint but the interior paint, blue date of manufacture sticker and SPID remain original.