[Eric H]

OK, I found this picture I grabbed from eBay a long time ago, it has the tag next to the resistor box where you have the Eyewitness tag.

This set doesn't have an eyewitness tag so perhaps it was located on the back instead of the chassis?

The 8-T-243 and the T-120 have both the Golden Throat and the Eyewitness tags glued to the back, someone here or at the ARF must have an original 630 back they could check.

Edit, my 630 has the Eyewitness tag in the same location as yours but it has the serial tag in the normal spot, I don't have a back, what does it mean, I haven't a clue, I'm totally confused now...
Maybe the AGC sets got the other tags on the back instead of the chassis.