Often, when someone modifies a CZ for SA only fire they'll replace the hammer, maybe the sear and do some polishing and spring changing to make things smoother, lighter, easier to pull the trigger and operate the slide.
Is it worth $600? They don't make them anymore. You can probably find one cheaper but it may need work to replace old/worn parts and refinish it, if you wanted it to look nice. Just over 6 or 7 years ago I bought a well used surplus CZ85 Pre B for a little over $300. Spent more than that replacing worn/damaged parts and getting it refinished.
If you to a google picture search you'll see CZ85s with no right side slide release levers. I even saw one with a smooth slide like the OP's pictures and one with a full rail slide, like a CZ75 SA or CZ75B .40 S&W. I liked that one.
CZ is one of those companies that turns out lots of variations of their pistols. When you think you've seen all of them someone comes up with one you haven't seen.
Good luck, OP.