Engine compartment restoration

[68SSrag]

New guy here.  I have a half dozen Camaro Restoration books.  None of them cover this.  I've search archives for this topic and didn't find my answer so here goes. 

Does anyone know of a book that explains the different engine compartment stencils and chalk marks, what they mean, where they go, what color, paint or chalk, etc? 

I am trying to spruce up my '68's engine bay.  Thanks for any help.

[Mark]

The chalk and crayon markings in the engine compartment were for the most part placed on the bare steel of the body before it was painted and they do not show on original cars.  The one exception is the PTB inspection stamps that were placed on the firewall of Norwood cars as the car was built indicating the body had been inspected for paint, trim and body irregularities.  These were placedon the body before the front end was installed and are usually under the fenders on either side of the car.  All the pretty restorations you see now with chalk markings and script on the firewall is utter BS and you can bet no car left the factory that way.  If you can't see it on your car now, don't add it.

[RamAirDave]

I've chalked firewalls before, but per owner's request (some like that look).  Ive found a ton of writing on the firewalls of cars, all under the black.  You also see the cars with all the Xs and -20, etc.

Except for one anomaly:

[Dave69x33]

As Mark noted below, the firewall markings on my 69Z (05A Norwood car) were found under the paint.  Attached are a few pics.

The "X3" = RPO X33 for RS Z28
The "D8" = PPO D80 spoiler equipment
The "2X" = HD radiator, but mark has not yet been confirmed
The "10" = RPO N10 duel exhaust

What I have been told from a number of judges over the years, if you can photo document the marks under the paint, they will accept them on top of the firewall paint.  However, since these numbers were typicallly not applied after the body/firewall was painted, I did not apply them to mine.