First 1967 383 installed in a Barracuda

So it was scheduled for 3/1 and shipped 3/10.

If indeed all 67 383 cars were scheduled to begin production on 3/1 the only way to determine what car was the first built would be to look at all the IBM cards, which Chrysler has, but they're not letting anyone sift through all of them.

On another note, the engine pad stamp tells when the engine was assembled, obviously, but could give some immediate info if 2 383 cars were parked next to each other and both had 301 on the fender tag.

Ordered car built to spec for Canada

I see 2 Accessory Group 36s, 360 Decor Group (G0 on tag) and 367 Formula S (F7 on tag).

Also, it appears there is 1 Accessory Group 35 of 358, buckets/console, body sill mouldings, as well as outside RH mirror and mag type wheel covers.
358 does not show up on fender tag, although I've seen a6 and b4, and sometimes just one, on the fender tag when 358 is selected.

Your car has the base hubcaps and no RH mirror.
I don't see the 529, iirc a 9 under the 1, for wheel lip moulding.
The 9 under the 1 would indicate wide sill mouldings. Mine has the J 4, indicating narrow sill mouldings. Not sure if the 0 under the G has anything to do with the wheel lip mouldings, but it has had them since day 1.
I appreciate all your help with this.