Search the web a bit too. I found this for removing labels off wine bottles. Some of those old labels are the same type of stock. Might help a bit?

http://www.centralcoastwinereport.com/index.php?q=how-to-remove-a-wine-label.html

^^^ this is actually a very good video. Your label should be the dry glue type where heat is used. I'm sure with some test and practice you'll get it just fine. It also shows how to tell which type of glue is on the label.