I was able to at least make a few restoration comparison photos for “Dumbo” and “Winnie the Pooh and the Honey Tree” (even though I still don’t have any of the mentioned tape masters I’m missing in order to create an actual video comparison; the ones listed with a star are the ones I’m missing):

Dumbo:

Versions Compared:
*1981/1982 (original VHS/laserdisc release; correct me if I’m wrong, but I believe the 1985-1989 VHS editions used the same transfer as well)
*1991 (Walt Disney Classics VHS/laserdisc re-issue)
-1994/1995 (Masterpiece Collection edition, also used for the 1999 UK/Australian DVDs)
-2001 (60th Anniversary Edition)
-2006 (Big Top Edition)
-2011 (70th Anniversary Blu-Ray remaster)

Winnie the Pooh and the Honey Tree:

Versions Compared:
*1981/1982? (original VHS/laserdisc release of “The Many Adventures”; correct me if I’m wrong, because I got the screenshot from “The Story Behind The Masterpiece”)
-1986 (original VHS/laserdisc release of “The Honey Tree”)
*1996 (Special Commemorative Edition)
-2002 (25th Anniversary Edition)
-2013 (Blu-Ray remaster; cropped into widescreen)

Missing from the photo above is the 1994-2000 video transfer used on the Storybook Classics VHS releases of the “Honey Tree”)