I've performed a similar project on a CZ82 that was missing almost all its enamel finish and had terrible grips, but was otherwise in very good mechanical shape.
If you only pay $100 for this pistol, this project will be worth it. Just be warned - detailed disassembly/reassembly of the CZ 82/83 is very difficult. There are some tiny and maddeningly complicated internal parts, and how they go together is not obvious.
It's possible - I did it with basic gunsmithing tools (and a little tool I made out of a needle to re-install the sear spring). But bag and label all parts, set aside at least a whole afternoon for reassembly, do it in a clean/organized space, and be prepared to get frustated as you try about 100 times to get that sear spring properly installed.
Here is a guide, but I recommend you watch a few youtube videos as well:
http://leolani.net/relics/cz82.htm
Those warnings aside, the old enamel finish (if the CZ83 has the same typical finish as a CZ82) can be removed with the "Aircraft Stripper" you can buy at Autozone, and liberal use of a copper brush. Prepare to put in some elbow grease.
Duracote HK Semi-Gloss Black in a aerosol can runs about $55 and is an almost perfect match for the original CZ enamel, but will be much more durable. I would just get the whole kit with the Duracote degreaser and abrasive pad. Follow Duracote's directions for preparation and painting religiously.
You'll just be Duracoting just the slide and frame. All the small parts and the trigger guard are blued. Birchwood Casey Super Blue cold blue should work well for these parts. The barrel is in the white/chromed, and should not get a finish - mask this before Duracoting.
You can reassemble the pistol after giving the Duracote a few days to cure. I would give it at least 3 weeks to a month to cure before any heavy handling or shooting.
Original CZ83 black plastic grips are still available and not terribly expensive, and there are tons of aftermarket options on Ebay and elsewhere. Most grips on these pistols will need some fitting, as there were slight dimensional variations to the frames over the years.
Hope that helps. Like I said, this is a worthwhile project, and totally doable. Just know what you are getting into.
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