I would agree with afultz075 about the CZ 83 frame layout and the challenges it presents for good grip manufacturing. My experience is with quite a few grips on a half-dozen frames that are both the older as well as the late production CZ 83 frames.
Agree on those Tillander grips having issues with fit. Have had to sand a couple and they never quite fit or felt right even after I was sent replacements. Just received wooden ones from Grips4u and while they fit on the frame, the inner dimensions make it very difficult to remove the magazine. The magazine barely budges when you push in on the mag release so you have to grab the mag base to pry it out. Have already spent lots of time sanding the insides of these grips and the mag will now just budge only half the time when the button is pushed. The mags for the 7.65 mm have a slightly different profile and seem to release much easier. Externally, there is a sharp edge on the lower front end of both grip panels that don?t match up well with the frame.
Marschal grips are expensive but fit well and magazines drop free. A couple of Klinsky grips have the same positive attributes for the CZ 83. However, I have also encountered issues with grips from Klinsky for the CZ 75 and Walther PP. Like the Grips4u ones for the CZ 83, it should not require this much fitting given the cost of these grips.
The carbon fiber ones from Prestige Grips are decent although they didn?t work on a particular 1986 frame as the safety was hindered from moving. Have also tried a couple of the cheaper, wooden ones on eBay from Thailand and they either were too thick internally and restricted the magazine or were too thin and cracked. This is the bane of CZ 83 owners who can?t leave the stock grips as is ??