It might be a common problem on old transfers, I encountered the same issue on my Technidisc pressing of SW, on that one, only some reels were affected, I think they just didn't scan the prints correctly sometimes, the widescreen format on video was also still relatively new back in the early '90's.
I guess most people don't even noticed or cared but I tend to spot these sort of anomalies and it irritates me. ;) Speaking about that, I wonder if Coily may perhaps be on the negative.