I believe the '48s (and likely other years around it) had the tags held on with screws as opposed to rivets. When I saw the '48 Custom my dad used to own in May, I took a picture of the tag, which I know to be original, and it's held on with screws (see attached) so that's why I doubt it was changed on the Craigs List car. I only mentioned it because it could be changed easily. You're more likely to see that on Z28s and Boss Mustangs than on KF products. The Linden green color was only available on the Custom (not the Specials) so it could be authentic. I'd really like to see it up close and personal.