none said:

Is there any sense of quality loss in the ITV end credit dissolve? Would this have been something LFL would supply, or to fit timing, ITV would have snipped the film and created their own dissolve?

Seems to be on par with the generation loss seen in the original, hard to see with the already bad source really. I assume this have to be the doings of the TV-station but it is the weird way they choose to do it. Attach the '81 crawl in the middle of the opening scene and create a dissolve to the revised credits instead of making the edit point on the last group shot.

none said:

I'm assuming ITV would have done their own conversion, figuring out which shots to pan/scan and which to squeeze. Are there many squeezed shots besides the credits?

Other than the added ANH-crawl and end credits there's no other squeezed footage.

If you compare with the original where the credit card appears in frame, it isn't centered because the way they choose to frame the scene isn't centered, which means no theatrical prints had this dissolve variation.