Sounds like a fun project.

Not barrel-related, but certainly CZ550-related is the extractor.

As with stock unmodified '98's, you may find the extractor does not slip over the rim of a cartridge dropped into the chamber by hand {not fed from the mag}. Some leave Mausers alone in this respect but I'd have that altered as I consider it a serious problem just waiting to happen {it has happened to me over the years with '98's}, i.e. if you fumble a load and the round goes up the spout, getting it out can be a bear or worse, impossible until a cleaning rod is introduced.

Another thing pertaining to the 9.3x62 is that it seems to be one fairly dramatically affected by the weight of the rifle. Since you spoke to the possibility of having a very light rifle this might be relevant. At standard or a little heavy weights common to sporters and specifically the CZ550, the recoil is relatively mild, but if the gun weight drops quite a bit you may find recoil to be unpleasant. If you don't mind that, it may be fine, but some fellows claim really light 9.3x62's are quite nasty kickers. Tho mine is stubby, it is not particularly light so I have not had that problem as kick speed seems slow tho I do get just barely kissed with the scope at times.