The burn mark is also missing from the 1982 UK TV broadcast of ANH.

It's significant because the print used for this telecine featured the mono audio track.

I am assuming the print was used for the April 1981 back to back 2 week theatrical engagment with ESB.

Now as to whether this was a print that was from 1977 with the new crawl spliced in-------or if it was a new IP struck specifically for this brief release is unknown.

ITV(UK broadcaster) may still have the video telecine or the actual print kicking around somewhere in their archives.