Czechoslovakia 1920/1973 - Fascinated collection with very rare postal items from an authority that doesn't exist anymore

I am collecting for more than 60 years many different collection as stamps and all philatelic material and Post-cards, Telephone cards, Coins and Banknotes, Rare and Old books and History books, Comix, Old Magasins, Chess In cases of 2 or more purchases from the same buyer the real postage cost will be applied and the excessive cost paid will be refund directly to the account given by the buyer.