I swear, you guys! Looks like you all jumped all over this question.
Thanks, and let us come to a consensus. Like Gary, I cannot believe Chevy would take the time to mask off or use one of their famous 'coffee can' covers. This bit of minutia was prompted by a friend's pic of paint work he was having done on his 69. His pic of his car's firewall showed this loom masked off. Masked off, I say! I thought, why? Seems I recall paint on my rubber part of the loom, but, hey, as a young buck I was pretty much a maniac with the rattle can, lol.
So, I decided I wanted to get the low down.