crimped shut rocker drain holes from factory?

So I just noticed that 2 out of 3 rocker drain holes in front of the rear wheel arches have been forcibly shut somehow. I tried prying them open with a screwdriver but that didn't do a damn thing.
Discovered this after beginning restoration of the rear window regulators and finding 2" of dust and lead blobs in the bottom of the body panel along with a plugged drain hole there.

Do I need all 3? I don't want to start messing with these if they're supposed to be that way. Really looks like somebody with gorilla hands and a pair of vice grips was on the job.

Car in question is 65 Barracuda