I really have no idea. I am sorry I am not a stamp collector. These were my dad's and he has passed on. I am not sure what hinged means, but I know they were never used. I am so sorry I could not answer this better.
I'm a stamp collector...and most of them are from Austria..their are 2 Germany that I can see...these will be a nice addition to my Austria collection..if I win them...my good friend Mike3303 has his eyes on them too!! Your new friend...China Mike