It will depend upon the HJ. Mostly which body plant and which assembly plant. For example, A Pagewood HJ van will have its firewall painted at Elizabeth and the inner guards paintd at Pagewood, so the paint will be slightly different.

This is from HQ Sandman paint specs dated 12/73, so i'm not sure if HJ was the same. It lists The plenum and "front body pillar outer panel" as GMH S228 (BLACK 599-00364), and the Front Fenders (underside), Wheelhouse Assembly (Underside), Front end frame complete and Radiator Support panel assembly as GMH S113 (BLACK).

The GMH spec numbers are the texture/gloss/quality etc ie the paint spec. I'm pretty sure S113 is slush black (hence why it has no Dulon code), which is just a slops bucket of left over paint from prior shifts all mixed together. The colour varies, hence why the statement above about different body and assembly plants. I'll double check that S113 is slush black. If it is just get some semi-gloss tuxedo with a few colours mixed in it if you really want a factory appearance. Otherwise just use a straight semi-gloss tuxedo black.

Now, next bit: HJ Features manual states "To improve engine compartment appearance all sheet metal and mechanical items are sprayed in clear lacquer". The page is dated 12/73. The text has a 5 pointed star next to it, and elsewhere in the manual it is used to show what is new for HJ. Cars are too old now, but some of you will remember in the 80's when these things were still being wrecked as pristine cars, the inner guards always looked to have a mottled finish, where in some placed the clear stuck and in others it had flaked off. Often the rubber hoses were the same, some glossy clear and some worn off. This will be because the lacquer was sprayed on once it was all done.