Its the predecessor to the CZ550 series. The main difference is that the action metal finish is not polished and the 2 postion safety works 'backwards' i.e. foward safe, rearwards fire. The earlier models (1970's?) had a flip up ghost-ring in the rear reciever bridge - very classy. They were shipped with 2 triggers: the fitted set trigger that was straight and had the small lever in it, and a traditional curved trigger that could be retro-fitted.
They were very common in my youth in South Africa and the amongst 'gun nuts' we were always dissapointed when someone had a 'Bruno' in .270 or .30-06 as they werent exotic enough for us. They came then in 2 main models, the Standard and De Luxe which differed in the stock only. The 600 is a standard length action that housed .270, .30-06, 7x57, 7x64 et al, the 601 was a short action that was .308, .243 and rarely a .223 and the 602 which was the magnum length action for .375 etc. They also put the .300 win and .458 win on the 602 which was less than ideal as the action was too long for those and it was common to see .458's with blocks welded into the magazine to shorten them, otherwise feeding problems would be common with the huge mag boxes in that action length. A ZKK .458 was the perfect candiate for affordable and effective reaming to Lott/Watts/Ackley versions due to this length issue. I believe the 602 might also have existed in 8x68S and .404. It did come in .416 Rigby too, but not for long as they changed to the 550 action, which of course still house that cartidge today.
They are strong, robust, all-steel working rifles. Ultralights they are not, nor are the 550's we see today. Arugably the 550's are better finished. The ZKK actions were rough but smoothed up nicely with a lot of use. I had a 602 Standard in .375 for while and almost all of my friends or someone in their family had a ZKK 600 or 601. I think a 601 in .308 is a great rifle - as close as you might get to a quality Euro made 'short Mauser' without breaking the bank.