@Pheroze The ZG 47 has the trigger entirely attached to the receiver whereas the ZKK mechanism is partly attached to the receiver and partly to the floor plate thus allowing change from curved to straight blade and vice versa.
Both rifles have safety catches (as opposed to trigger blocks) BUT the ZG 47 safety catch is mounted to the bolt whereas the ZKK safety catch is attached to the receiver.
The ZG 47 has a barrel-mounted backsight with screw adjustable windage whereas the ZKK version is tapped from side to side. Many ZKKs came with a fold-down peep backsight.
The ZG 47 is more finely finished than any of the ZKK models. The ZG47 is a standard large ring action. The ZKK 600 is also a standard large ring action BUT the ZKK 601 is a short action version for the 308 Winchester, etc. although it was also chambered for the .223 Remington; AND the ZKK 602 is a true magnum action.
All these rifles use a pre-64 Model 70 type magazine BUT the ZKK has a so-called reverse-round follower, with the first cartridge going in on the left hand side because that is easier when thumbing cartridges in, one by one, especially with a scope in the way.
Both types use the same interchangeable bead foresight, still available in various heights from CZ-UB, etc. (with aftermarket options from Recknagel) but my ZG 47 has a brass bead and every ZKK bead foresight I have seen was all-steel.
All rifles use the same two piece mount rings and the one piece mounts for the ZKK 600 will also fit the ZG 47 and the standard length CZ 550.
There are various qualities of ZKK, dependent upon production era and I am not going to enter that particular ‘hornets’ nest’ of debate nor am I am going to discuss the two types of ZG 47 trigger. Mine provides ample accuracy and in prone position my .30-06 is just as good as my 7.62x51 target rifle built on a Spanish Air Force action with Kongsberg barrel.