In the 1991 VHS release, after the "Feature Presentation" card fades to black, at first a film called A Boy Named Charlie Brown (1969) starts playing, and it goes up until the start of its opening credits, then you hear someone saying that they put in the wrong film. The film stops, a quick reel change slide is put up, and then the real movie starts.
The credits first say "Twentieth-Century Fox presents a CinemaScope Picture in CinemaScope 55", and then they go on to say "Darryl F. Zanuck presents Rodgers and Hammerstein's 'The King and I'".
Opening credits prologue: Siam 1862