On the surface the older models appear identical to the newer versions. My 2009 PCR has a slightly different firing pin block plunger than my 2021 versions. I think CZ has incorporated more mim parts in the newer models such as the sear cage and the trigger bar. I know some kitchen table engineers sneer at that but done right it's an effective and quality process. My new models are just as accurate and reliable as the old model.
