I didn’t think there were multiple HD sources. Is the AUS Blu-ray actually a different source than the 2009 release?
I have this:
http://www.blu-ray.com/movies/Wallace-and-Gromit-The-Complete-Collection-Blu-ray/5984/
The AUS 2016 Blu Ray was resourced from the original film negatives and maintained the original 25fps framerate, whereas the 2009 Blu Ray which is currently available in UK and US had the first 3 shorts slowed down to 24fps.
Another thing worth mentioning about the AUS Blu Ray (and I believe the original 2009 BD) is A Close Shave has been cropped to 16:9 wheres when originally broadcast on BBC1 back in 1995 and on my 2005 PAL DVD, it’s 4:3 open matte.