Omar Sharif

The 5.1 on Sony 4K Blu-ray is from the 1989 70mm mix. The original is 4-track. not on the disc.

The original mono mix has bad pitch and sound quality issues on the Shout! Factory Blu-ray and is terrible sounding. The LaserDisc PCM mono is very good but sounds a tad muffled in comparison to the MGM 2004 DVD mono at first listen. Yet the DVD mono has the volume of the entire track normalized so that effects and music remain at consistent levels which they don't in the LaserDisc mono-meaning that the jokes and gags hit harder in the LaserDisc mono because the mix varies as it was intended. It may be that the same source was used and then EQ'd and processed for the DVD boxset as all the mono mixes were messed around with. For example, when the hunchback disguise goes off with the explosions, the DVD mono has everything at a mostly consistent level. On the LaserDisc the effects build and fall off in loudness so the intensity is entirely different because they were mixed that way for comedic effect. Another is the piano smashing-on the DVD mono it's at the same level as the rest of the scene. On the LaserDisc it's loud and aggressively so which again makes the gag hit so much harder.
Again, the remixes are existing MGM ones and not good. The 5.1 remix on the Shout! Factory Blu-ray does not have pitch issues but the stereo remix does.