Thanks to those that've replied (especially with other pics and links), I'm learning alot about these simple yet complex classics along the way.
yes they are paint inspector stamps.
you would have seen similar ones on my 66 gt convertible over the weekend. they are unique to dearborn cars.
The ones i have seen are normally white or yellow in colour.
Phill, I was in awe of your car that I only took a pic from the back, the attention to detail was outstanding, from your knowledge were all the stampings around the engine bay the same or did they differ slightly from shifts to types of cars/colors? if so, I could apply the markings you used when the time comes further down the track...
Before someone starts have already done the design work on these (too bad they were not used on more cars) along with about 150 other paint stamps
Jeff, if you have some of the Dearborn specific designs and are willing to share, I'd appreciate that.
Thanks again guys