JayBe
·Great watches, especially with their story that makes them personal for you.
I asked because I've lately seen couple of Certinas online, with a Polish day disk, which looked kinda similar to the one you shared here. 😀
From a short online research I did, it emerged that there was a store chain in Poland formed in the 70s during the communist time, where only Dollars where accepted. Among some other western products, it sold watches. Omega, Longines and... Certinas we're discussing here. (Funfact, even some Omegas had the translated day disk).
Yes, this state-run chain was called Tuzex in Czechoslovakia and most of the foreign goods were only available there for special bonds that you could purchase with foreign currency. But it was not that you could buy it exclusively there. I was happily born to late to bother with this, so I cannot describe it from experience. I recently showed a Zenith here, that was purchased in 1965 in such a store in Prague. But I also have an Omega that was purchased in a regular jewellery store in Prague in 1973, based on the receipt.
This is the receipt from Tuzex (195 Bons should be equal to about 1000 CZK at the time):











