Hey Greg,
back in the early 90's when I was roll hunting Lincolns I saw a lot of that. Yes, gas bubbles. I've still got rolls of Lincolns from various years up through about '97 or so. I don't remember exactly because I haven't looked at them in ages. They just sit in a roll storage box in there little plastic coin tubes. I have maybe about 12 rolls or so,all AU and better. 2 or 3 rolls of 82's, several other solid date rolls, and some mixed date year set rolls. A lot of those coins have those gas bubbles.
It seems that as the years have gone by the plating process and manufacturing got better and you see less of that. I seem to remember quite a few of the 82's having that. It was actually an easy way to tell the zinc from the copper! Beyond that I never tried to figure out which ones were which. Maybe someday I'll care!
But for now I have a bunch of pockmarked Lincolns. And you have one too!
Steve