little research on where this stuff came from so far.
Apparently, it's not a passport but a museum pass from Austria in the 1920s


No idea how much of this collection was his but most of the covers and postcards were addressed to him so I googled his name a bit and have come up with this:
http://www.dictionaryofarthistorian...g/suidaw.htma bit about his art collection
http://txtell.lib.utexas.edu/storie...06-full.html"...The story begins in Austria in the late 19th century, when William Suida began collecting art from the late Renaissance and Baroque periods. Forced to flee from the ****s in 1939, he came to America, where he continued collecting. His daughter, Bertina, shared his passion and, more importantly, his eye for art--that ability to pick out the masters from the impostors, developed from careful study. A connoisseur like her father, Bertina joined him on his tours through Europe, expanding the collection.
Bertina met Robert Manning at New York University, where they both were studying at NYU's Institute of Fine Arts. She married the native of Mart, Texas (near Waco), and together they began to build a collection of their own."...
Haven't found anything mentioning him as a stamp collector as well yet but he must have been with the amount of things with his name on them.