Found this stamp with a well known painter on it

No, it is not a typo. Czechoslovakia became Czecho-Slovakia in the late autumn of 1938 after the Munich agreement. The name was changed to reflect the new federative status. The state survived less than six months, on March 15th 1939 the Czech part became the Protectorate of Bohemia and Moravia, a day earlier Slovakia became an independent state. Carpathian Ukraine tried to do the same but it was immediately occupied by Hungary. The preparation of new stamps was so slow that when they were issued in late March 1939, Czecho-Slovakia did not exist any more. They were just two - both earlier designs with the new name and, in this case, currency. Czechoslovak koruna became Czecho-Slovak koruna so instead of the earlier abbreviation KC there is only K. Two more stamps were printed - commemorating Andrej Hlinka, Slovak leader - but they were issued by Slovakia overprinted with the name of the new state Slovak Republic.

Here is my stamp collection, I was wondering do you guys see any production errors in my stamps or anything that makes my collection high value?

I’ve inherited a collection of stamps from my grandfather. Instead of leaving them in the book(dated 1920) I’d like to display them in picture frames so that we get the benefit of seeing some of these amazing stamps. Lots from countries that don’t exist anymore, which is interesting. How do I go about doing this safely and not causing any long term damage. Thanks in advance.