@mitu thanks for the reply and great suggestions I hadn't considered!
As it turns out, I was mistaken. The pacman.zip file was not in my roms folder. I won't get into the details since this is a sensitive topic (regarding legal gray areas and fair use arguments) but suffice to say, way back ~20 years when I started this hobby, I had to hunt for the original zip file and I never included it in my archive of the internet archive 0.256 rom set.
Still don't understand why it's not part of the merged roms internet archive.