I think he meant poly coat finish on the frame, not a frame made from polymer.
I have one Pre B CZ 85. Pretty rough when I got it. Still had middle eastern dust under the grips/grip screws and mixed in with the old oil/powder residue to make a fine lapping compound. Pitted chamber/barrel (corrosive ammo?? You'd think it was too dry over there for a gun neglected after a rainstorm to rust). Some rust on the surfaces outside, front sight damaged, a little.
It's purty now, though. New barrel, new cerakote finish (two tone) with an adjustable rear sight and 1911 fiber optic front sight. Shoots pretty good, but the trigger (original parts inside except for the springs) isn't as good as some of my CZ75's that I spent more time/money on for parts/polishing. I still like it. Just not an EDC gun so it seldom gets shot.