Changing dimensions

While it is common knowledge that the physical dimensions of publications are tending to get smaller all the time (at the very least saving slightly on paper expenses), I was surprised to find that four different printings of the same musical text (NBA Ser. IV, Bd. 2) are all of different sizes; different margin sizes meant that the "aspect ratio" is not even identical.  I had these on hand (don't ask why...):

1) 1958 East German printing, NBA, but under the imprint of the Deutscher Verlag für Musik (DVfM 5009), measuring 25 x 32 cm [ratio = 1.28]

2) 1958 Western printing, still as NBA, but with the Bärenreiter imprint (BA 5009), measuring 24.1 x 32.8 cm [ratio = 1.36]

3)  1983 Bärenreiter offprint of NBA text  (BA5172), measuring 24 x 33 cm [ratio = 1.375]

4)  Later Bärenreiter offprint (still BA5172; this copy says "15th Printing 2015"), measuring 24 x 30.3 cm [ratio = 1.26]

As far as I can tell, all four copies present the same text.  There may have been minute corrections over the years, but at least one typo that I noticed (p. 99, b. 10, middle stave, final rest missing) is identical in all four copies.