I got the collection box. The first film is stereoized but this practically makes it expanded mono with the stereo score in full stereo inserted. Impressive dynamics but very distracting, and there is also some tape damage.
According to the labels 2 and 3 also got the same treatment.
This was the widescreen debut of the sequels…and they felt it a good idea to remix the mono in he big collectors box…go figure…