Likely from old HD material stuck a few years back via MGM. I've seen a bit of the 720p version with hdtv logos and it looks like a cross between upscale and higher res master with noise. The Panthers all look rather iffy on DVD, as they are the exact same transfers as LD with tinny lossy audio. The first film got a BD re-issue but it really only tidied up the old scanned material and isn't really benefiting of a Technirama picture.

The audio for all the films (I don't have Revenge or Trail on LD, so I'm assuming for them) is all clearer and more robust on LD due to the PCM and lack of loudness compression. That said they do get a bit noisy and peaky at times but that is to be expected for the age.

Of all, Return has the best transfer because Universal had to do a remastered version of the Image DVD (which itself used their remastered LD transfer) and instead made a nice and very good looking HD master which is probably sitting on a shelf somewhere...or not as it could be up in smoke as is their mid 2000's stunning master of Brides of Dracula that went up in the studio fire.