I have about 15 bound collections of 6 months each National Geographics. What I am wondering is if how they are bound destroys or impairs their value. Each stack of 6 had 3 holes drilled through them and string used to bind them. Over that, in most, a stiff cardboard front and back cover was attached with linen tape. The tape does not seem to adhere to the spines, however. Some so not have the cardboard covers and those are a bit dogeared on the outermost covers. Some of those were also reinforced with clear tape at some point in time. Obviously, these were in a library for years.
The magazines are complete with ads but no supplements. They do not seem to be missing any pages and the interiors are in great shape. I have attached some images of several.
In the condition the pictures show, your volumes have no value.. Issues from the 30's thru the 60' s are very easy to come by in excellent condition..