I could have gone with four layers of glass this would have been enough. I trimmed it up with a fine toothed jigsaw and brought it back to thickness with a grinder to make everything fit.
I will do a few tries on the layout to see what works.
I am not sure I am enamored with paying a fortune for a poorly performing 1970 audio unit just to keep the look.
Still considering what will work in a dash layout for a modern usable Pantera that can deliver on driver comfort.
Any suggestions would be welcome.