none said:

Catnap and Puggo Grande (until proven otherwise) appear to be the same, a 16mm capture. [and there's also the theory that they are the same print, captured years apart]

I see, didn't know that. At least now there seems to be a connection between the composite and credit variation. The only question mark now is why the cloudy composite reappeared on the NTSC video master.

It seems pretty logic that they took the opportunity to revise this composite at the same time they revised the credits as it is located on the same last reel. Maybe a possibility of more subtle fixes in the Death Star battle as well.