Hey Woodstang,
The Rickster is a 73 Mach 1, but it had a wicked tear in the front bumper, and although it's a bit different from your 72 bumper, some of the techniques I used to repair it may work for you. The bumper repair is on page 9 of the build thread. Yes, I also referred to the motortrend article and tutorial that Steve mentioned above to figure out how to do the repair. I hope this helps. https://7173mustangs.com/threads/the-rickster-a-73-mach-1-work-in-progress.16772/page-9#post-402822