The Stovebolt Site Forums The Shop Area Paint and Body Shop GM chrome bumper question

I have recently checked two bumpers and found them both to be MBC. One was off a 49 Chevy pickup. The other was a rear panel or burb bumper from an unknown year between 47-53. I realize opinions are like Adam's apples, but I would venture an opinion that MBC was a vendor of new parts to GM (possibly only at some assembly plants.)