its not what you think it is
Shuie,
I must confess those 5 black circles on the bumper are black vinyl tapes.
I got a little creative about 4-5 years ago and came up with the idea of trying to mask the hole openings for the plate holder mounts by taping those black vinyl decals to simulate what would appear to be openings for a front cooler since I didn't want to run front plates. Of course I also looked to whether a front cooler would actually fit in that location if I wanted to mount one with the stock bumper. Only way it will is to open up a section of the front inner nose panel where a cooler would have to fit through. Even if you got one to fit in that location, you wouldn't have enough clearance behind it for the air flow to go through and will only create air turbulence with no where to go. I guess it might work if you cut through the opening and built a ducting where air will flow through downward and out from underneath the front pan. Too much work and cutting involve and may not be worth the effort not to mention cutting up the front nose and pan for the opening and may even cause problems at high speed.
Sorry to mislead you into thinking that I came up with a briliant idea on how to mount a front cooler in the stock front bumper. I've since done away with the decals and mounted my front plates instead. You gotta admit, it sure looks trick in the photo. ;)
good luck with your 72.
Cris