I did, but it was a few years ago. At the time, they had a CZ outlet store downtown, just a block or so off the main tourist pedestrian walk in the city. I think it was to the left, as you walked North towards the national museum. It was great. Mostly clothing gear with their LOGO, but a full gun-shop too. Europeans are all about that extensive scroll-work on the metal, and they had several examples of $5k CZ-75's will all kinds of decorative scroll work. Not really my style, but still kind of cool to see. And they had any spare part you wanted. I picked up a slide release, some grips, and a neat CZ padded pistol case you can't get here in the US - and a shirt.
Prague's a great city - I loved it. Good food, good people, hot women. Be sure to hit a symphony, even if it isn't your thing. They're cheap and amazing there. Mucha the artist is from there, and they have a Mucha shop I think really near there, maybe turning right instead. Lots of really great Art Deco paintings of beautiful women and things that are very tasteful - he was the inventor and definition of the 1920's gilded era style.artwork so oft copied, and just amazing stuff - worth a moment to pop in. Sadly, the Nazi's killed him, the bastards.
If you have time you can go see BRNO, where the brother's grim are on public display, and you can see the original pea plot and monastery where Gregor Mendel discovered genetics. It's mostly a beer brewery now - God I love Czech Republic.