Here are several pictures of the underside hood area from unrestored cars. One thing you will notice is on all of them the 'front lip' area, for lack of a better word, remains white and the black paint is painted on afterward, and with not much precision in some cases. The black seems to be a flat to a satin type of finish and is brought to and oversprayed up to the 'lip' area. I'm guessing that the lack of precision in painting them relates to the theory that at the time of painting, they were all intended to receive underhood insulation, so the painting didn't have to be so precice. It wasn't until the hood was matched up with a body that it was determined to be on a H/O and it would not get the insulation. Special thanks to Joe Fotchkey, Dennis Taylor and others.
The following under hood markings appear to all be in original 'wax pencil'. The first 2 show the 'W46' marking on the drivers side along the hinge attaching area. The other markings are 'X''s that I'm told were to designate that the hood was not to receive underhood insulation when it was coming down the assebly line.
The following under hood markings are also in 'wax pencil'. Several have numbers written on the underside of the hood, unfortunately I am unaware of what the designations refer to.