It would be helpful if we could see some photos of unmolested engine bays, with the engine out. Not finding much via the Google machine. I am guessing they were painted all body color? No visible primer or black undercoat? Ours is pretty messy looking.

Click to view attachment

Yes, body color only. Anything else is non-original (and often hiding rust or other damage).

Did they have firewall sound proofing pad on period correct 914-6???

The above picture does not look like it ever had a pad.

No, 914-6 did not have anything on the firewall.

Real Porsche’s make noise and real Porsche enthusiasts like the noise a six makes. 914/6 didn’t need no stinking noise insulator. Had to pay extra for that glorious noise!

So they miss the fun of finding surprise(?) rust in the firewall.

That's also why I never really cared that the radio and speakers worked, couldn't hear it anyway.

914 6s had sound deading on the interior of the firewall.
The thin (but heavy !) rubber/asphalt like material was form fitting to the panel and
was glued in place.
It may have been in all early 914s

Can anyone recommend a source for spray can touch-up paint matched to color? I'm not going to have time to do a proper spray job and meet our deadline. A decent color match out of a rattle can would still be an improvement for the time being.

I found this Automotive Touchup site that says they offer Adriatic Blue aerosol.

Tower Paint used to provide custom spray cans, do not see them any more on the web. Lots of other choices though.