Yeah, my Mach 1 was built in the San Jose plant. We don't get snow in my area, and ice is rare so the roads are not salted.
From your pictures, that finish you are referring to almost looks like the "Trunk Finish" splatter paint. I cannot say if mine ever had it. The previous owner my older brother bought it from we think was the original owner. The previous owner told us it was his wife's daily driver until they parked it because of a small accident. I don't recall seeing that splatter paint finish in the engine compartment when my brother and I looked at it. Anyway, my brother dismantled the car completely, sent the body off to a paint shop, then he suddenly passed away. That is where I inherited it. So I have no detailed information of the car before it was sandblasted and body work started.
You are correct, I have seen that same finish in trunk compartments before. I forgot all about that. Maybe the "Trunk Splatter" guy was stationed to engine bay paint duty when this car rolled down the line. I have never seen it in the engine bay and firewall like this before.
It looks like somebody did it after the car was built. I only think that because they didn't remove the starter solenoid and voltage regulator. Instead it looks like they kind of carefully sprayed around them. Plus they sprayed the shock bracket. I'm guessing somebody wanted to repaint the engine compartment but not take the time to prep it correctly for paint so they used this "Trunk Finish" instead.
I've used this stuff on the interior of a 1956 Ford F100. Well, everywhere that wasn't sprayed the body color and ultimately got covered by carpet, upholstery, etc. Required surface prep is almost zero, it hides a lot of imperfections, is extremely easy to spray, and has a clean looking finish. But, an engine compartment is not the right place for it.
Thanks Steve, I have never seen it in an engine bay before. I don't think there is any reason to preserve or replicate it on the restoration of this 69 Mach 1. I just saw it as quite unusual and figured I would share it to see if any others had seen this before.