The Kadet hit has to be fit to the pistol it will be used with. You have to remove a small amount of metal with a file on the bearing surfaces of the kit itself to make it fit the gun. That means though that the kit will always fit and work best with the gun that it's been "mated" with. You could file enough away to make it fit any CZ 75, but then the tolerances will be looser and accuracy will suffer. My advice is to dedicate the kit to one specific gun
Well, actually, fitting on other guns shouldn't have much effect on accuracy -- as the slide doesn't move.
The barrel and slide are fixed, with just an insert moving. The barrel stays where it is -- and the sights and barrel stay where they are. Its like most .22s -- a fixed barrel. As long as the barrel and sights keep their relative positions (and there's no reason they shouldn't) a sloppy fit on the frame shouldn't really matter.
I have a kit on my 85 Combat. It is fitted to that gun, and I've never bothered trying to make it work with my other CZs (which come and go.) I've also, presently, got an 75 Compact and a 75B SA, now, have had many different CZs...
This kit will only fit my 85 Combat without mods. It could be made to work with the 75B SA and Compact, too... but why bother?
If you want an accurate .22, the Kadet Kit is great -- if you already have a CZ.
If you want a VERY ACCURATE .22, the Marvel Kit is exceptional -- but quite expensive -- if you already have a 1911.
From scratch, having both a CZ and a 1911 -- my choice would depend on what I wanted to do. If I wanted to practice with my IDPA gun, cheaply, I'd probably get the Kadet Kit. But if I want to do some SERIOUS Bullseye-type competition, I'd get the Marvel. (They guarantee a sub-1" group at 50 yards. Not many other .22s will do that.)