My DVR clocked the (restored) TCM print at 1:12:45; AFI catalogue lists it as 74-75 minutes, which reflects their two different footage lengths: 6685 & 6747 feet. So it looks like bits and pieces must have gotten lost over the years.
shareYou have to bear in mind that a DVD runs 25 at images/s, whereas in a theatre, it's only 24 images/s! This may explain the differences in running time. You will realize this on other DVDs as well.
shareDVDs in Europe run 25 frames-per-second, DVDs in North America run 30 frames-per-second (60 interlaced half-frames, technically), standard film projection is 25 frames-per-second in Europe, 24 frames-per-second North America.
The point everyone seems to miss is the frames-per-SECOND. The number of individual images shown per-second will not change the number of seconds in the original film.
"Film is a mosaic of Time."
-A. Tarkovsky