under body finish on 1974 Csi (Australian)

[Gizmothumper]

Dear Members,
I am in the process of restoring my CSi. Any info re the under body finish on my 1974 csi? The original colour appears to be a light grey paint under a resonably thick (dark grey) sound-proof coat. Did the original finish underneath have a colour coded finish (Golf yellow). Or do I finish in grey, black. I was thinking of starting off with a POR 15 base, then a sound proof coat.

Suggestions please.

 

[Malc]

The grey paint is the factory primer.
The thick grey stuff is the laughable attempt at rust proofing and sound deadening.
As far as I am aware the underneath was finish the grey soundproofing rather than a top colour.

Personally I have stripped the bottom of my car (aka the bucket) and used a good zinc based primer, will then use black paint followed by underseal

Malc