Thanks for the warm welcome, everyone! I am moving ahead on picking up my Vz.58, and am very excited. The ammo/parts availability concern is not a big one for me, as I stock parts deep, and have the budget to put A LOT of ammunition away. I have done this with the NATO rifle calibers already and have many redundant sets of spare parts for my ARs, and will have no trouble doing so for 7.62x39 and Vz.58 spares.
I never shoot steel-cased ammo anyway, so I would be using the non-Russian ammo anyway. I also figure that once the Russian ammo can't come in anymore, the huge number of 7.62x39-chambered firearms in this country will induce domestic manufacturers to start producing economically for that caliber, and cause the Czechs, Serbians, Bulgarians, etc. to step up their production as well. I am already looking forward to handloading for the cartridge, as I have a lot of once-fired brass I have collected over the years, CCI200 primers, H4198 powder, and just ordered some Hornady FMJs and SSTs.