I never much thought about it, but I wonder.
I had a Pre-B CZ-75 - a 1989 model I believe. It was the lower one in the comic book photo. I now have a pre-preB - a 1979 model, which is like the upper one in the photo. The slide and frame on my 1979 model saw much harder use than the later 1989 model, yet are in better shape than the condition of the 1989 model when I sold it.
This is all completely non-scientific, and is just based on my own recollection. What I can do is present you with the condition of the 1979 model, and allow you to compare this to the later models for your own analysis.
I fired thousands of rounds through that 1989 pistol, and eventually sold it because I thought a Baby Eagle was better (I do miss my old 22 year old body, but definantely not the idiocy of the 22 year old mind). I do recall when I sold it that the enamel finish was starting the bubble, the kidney shapped hole in the cam under the barrel was starting to get peened open, and the slide/frame rails lost their sharpness as well. I assumed this was nominal wear and tear, the gun still seemed to function fine.
To continue my rambling: I started to miss that gun (The Baby Eagle was a random jamming fiasco that had sharp edges galore). Some years later I decided I wanted another just like it. But by then, the dang B models came out. If I wanted a CZ-85, I'd have bought an 85: I wanted a classic melted looking CZ-75. So I looked around and finally settled for a 1979 era CZ for a few hundred (I say settled because the slab sides weren't as melted looking as the later Pre-B design). It was as pictured in the top of the above image. Not really what I wanted, but my friend needed some money and knew I was looking for a classic CZ.
The history of the 1979 gun was rough. We were told it came into the US from some kind of South African military/police service. My friend and I both saw its original condition when it came into the gunshop a few years prior - and it wasn't pretty. It wasn't even functional. That gun had seen some serious use and abuse. The slide stop pin was visibly bent. To show you what the surface of the gun looked like then, here's a photo of the original grips:
The entire gun looked that way. The finish was shot. The gun had obviously not only been abused, but had been fired a heck of a lot too. Here's what the seer looks like, see how worn it is (still got plenty of life left I bet, but I probably ought to replace that)
Here's the original hammer. Which is still a great hammer - the sear surfaces look decent enough, but the face is pretty pounded. (I just replaced it this week because I got tired of a bloody web after IDPA matches from the hammer bite). Actually, it's probably not the original hammer, since it has the half-cock notch.
The above illistrates that this 1979 pre-pre-B has seen far more use and abuse than my original Pre-B (1989 - the one with the worn slide rails). Anyway, the 1979 gun was refinished and the non-functioning parts were replaced and my friend eventually bought it. It still has original frame, slide, barrel, and most of the internals.
Yet, the edges of the slide rails on this gun showed little to none of the rounding wear I saw on my 1989 Pre-B.
The kidney hole in the barrel looks very good:
The frame rails looked good too:
I don't have my 1989 Pre-B with me anymore for a direct comparison, and memories can be funny things. But from my experience, I will say the claim that Pre-Pre B metalurgy was harder than Pre-B's seems credible enough to me. Not trying to diss the Pre-B's. Great guns and I'd be happy as a clam with one.
