I just got my SP-01 kit, which came with absolutely no Kadet specific instructions. I was relieved when it slipped right on the SP-01 lower and feels like it fits very well; I would have been up the creek if it required any fitting.
From searching the forum I discovered the purpose of the red and blue springs. Come on, CZ... how hard would it be to include a one or two page pamphlet with some basic info with these things?
So, the next stop is the range, but so far I am very pleased. The test target is very impressive... I hope my results are close to theirs.