Wayne at AHR did the CZ#1 Upgrade on my 500 Jeffery and I was thrilled with it. It cost $500 (about 4 years ago) and included installing a M70 type 3 pos safety, replacing the CZ set trigger with a single stage match trigger, and straightening and filling the bolt handle. None of these enhancements were needed, but I wanted them. I had absolutely no issues with any of Wayne's work and he is absolutely great to deal with. Here's a picture of my 500 Jeffery (you can see the safety and bolt handle)