Regarding '67 #1061, this link below includes more photos, showing a GT stamped valance. The one photo posted here is difficult to see it at the angle it was taken.
http://www.import-connection.com/index.php?page=item&item_id=769#1061 was built at Ford SJ 2/14/67 and completed by SAI 3/10/67.
I believe the stamped GT rear valances start appearing on the Ford SJ built cars around early February.
The SAI change notice was sent, and marked received by Ford on 1/25/67. It asked for an immediate running change.
We've seen the tail light panel changes start at SAI (including this car) around early March and continue with the other variations until around mid May. I've was working with JD and Dave, identifying and detailing all the changes, and sorting out when they happened. We have not been able to revisit this as a team since the new registry was put in motion.
The Hybrid hoods and trunks, appear to linger a little bit longer in the production run than initially thought, but this is also ongoing research.
As an example, Dave Mathews found a car completed in the middle of March with the hybrid parts, so #1061 does fit the pattern here.
I'm finding that trying to segment these cars into three distinctive groups (early, mid, and late builds), does not work well to define all the numerous running changes.