U.S. TV airings of the films were always on tape, either from the time-compressed laserdisc/CED transfer (HBO) or the VHS/Beta transfer (CBS), both of which were originally released in 1982. I am assuming that ON TV's one-time airing in September '82 came from one of these.

The ITV broadcast, however, does seem to be from film chain. It has that blown-out, yellow-greenish look I associate with old film-chain broadcasts of movies. I don't know if it was run live, or if it was output to tape by hooking up a VTR to the film chain. Since this version was still running on ITV in 1987, I'm guessing that eventually it was backed up on tape. And unless every broadcast was at the same time across the entire network, each region would have to either have their own print or their own tape copy; my theory is that one print was sent to ITV, then backed up to tape.

In general, for widescreen films, stations weren't given widescreen prints to crop themselves. They were given flat Academy-ratio prints, derived from a cropped internegative made with an optical printer. This same technique was used to make prints for airlines. Cropped flat prints of at least the first SW have turned up on eBay in the past.

As seen in old videos and TV broadcasts, the Greedo scene was reformatted for 4:3, with new subtitles added optically (not on video). Even though different transfers had different cropping choices, if you compare the Greedo scene, the cropping is identical in every version, because they were all sourced from the same cropped and re-subtitled element.

ITV either received a completely cropped flat print, or a widescreen print with the cropped Greedo footage spliced in. I'm leaning more toward the former, but I don't think there's any way to know for sure.