Very nice GK.It looks in good buckle.
The mounts are the same for the CZ's and the ZKK's.Just don't do the back one up too tight as it compresses the peep assembly.

I would love a 7x57 in the Brno's.I am trying to get a Brno model 21 in 7x57 out of a mate of mine but no luck yet.It has the spoon bolt handle,different cocking piece and twin set triggers.