A Body Firewall Insulation, HELP! PIC's

I no longer have later than 70 example here. I don't know what still exists in my pre 70 examples either. It's supposed to warm up over the weekend so I can have a look.
I have to assume any changes in the insulation were related to changes in other equipment. Like when a remote hood release was added that cable needed to pass through somewhere.
A foot operated park brake mechanism appeared around 75 too.
Sometime around 1972 a aftermarket vendor built and supplied a a/c package for dealer install. At first glance looked identical to the factory a/c . Perforated break outs in insulation may have been related to this.
All just edumacated guesses :)