Cz or vz it doesn't matter does it? Only difference is the vz has the Fa disabling block machined into the reciever and the cz converted auto recivers have the same block just welded in. Both are basically the Same and do the same thing, stop you from putting Fa firing parts into the receiver.
I'm sure there's some welding of extra material into the trigger and some other bits, there would have to be to move the trigger pull further to the rear from the get go. Then maybe some work with the main spring or springs on the trigger? Would definitely be a lot of screwing around.