Congrats brewman!

Usually the action on the CZ550 can be made smoother by polishing the bolt, the raceways and the feed ramp. Some people like to change over to a model 70 style safety. Parts can be purchased from American Hunting Rifles in Montana, USA. Some CZ550s have a good trigger and some not. If not, a stone can improve the surfaces and make the pull smoother. Personally I would have the action glass bedded and the barrel free floated. During this process I would have the stock relieved a bit at the rear tang to avoid stock split at the wrist. The recoil pad can be improved with a Pachmyr Old English style pad. And the bolt handle can be improved by replacing it with an Obendorf style bolt handle. Some guys do not like the factory iron sights on the CZ550. You could look at the sight offerings from Recknagel/ERA in Germany. Also the barrel on your rifle from the factory is longer than necessary. Personally I would chop it to 21 inches.

Good luck!