I second the thumbs up on DWJ, bought 6 or 8 from him , all excellent . Bought 2 older CZ's from another that I regret, one from a VERY well known importer was described as blued and it was polycoat. Took forever to get a refund.
Have upgraded several of my pre B's . Really like the SAO using a TS hammer from CZ custom, take advantage of the wide hammer slot in all but the latest preB's. With the standard SAO trigger this is an amazingly cheap upgrade and the results are outstanding