10 hours ago, Zed Head said:

I got curious so I looked in the GI pages of the FSM's. 1972 seems to be the first time they describe the stamping of the identification number on the firewall (cowl).

I wouldn't take that literally if I were you. Their intent was to convey information on location and form in an easily understood and digested nature for people who were used to the national vernacular of their automotive scene, not describe the process with which is was executed.

That's pretty cool! I had thought maybe the firewall was labeled before being included in the chassis but you're saying the chassis was complete and the fixture was mounted to the chassis and the ID number was applied then...

14 hours ago, Zed Head said:

I got curious so I looked in the GI pages of the FSM's. 1972 seems to be the first time they describe the stamping of the identification number on the firewall (cowl).

Incidentally, you might be interested to hear that the Japanese market FSMs use the term 打刻 ('Dakoku') in relation to the individual vehicle ID on the firewall. It translates as 'Stamping' in English.

They use the same term for the engine number and the engine bay tag, when they are clearly performed with different processes to that on the firewall. Again, I would not take it literally. It is similar to saying that something is 'written' on a page when it is printed, and vice-versa.

1 hour ago, Patcon said:

That's pretty cool! I had thought maybe the firewall was labeled before being included in the chassis but you're saying the chassis was complete and the fixture was mounted to the chassis and the ID number was applied then...

Exactly that. The engraving fixture hooked onto the firewall in a fixed position (one for RHD, one for LHD) and the operator did his stuff.

99.999% of the time he got it right. The rest of the time stuff like this happened: