To make a CZ Sharptail Coachgun SASS ready I did the following:
Lighten hammer springs. Lighten lever spring, lighten sear springs, Shorten cocking rods to change timing so the shotgun stays fully open. Lightly funnel chamber mouths. Reshape the top of the extractor into a diamond shape.
Used springs from a generic English light duty Wolff spring pack for hammer springs. Used springs from a Home Depot 85 spring spring kit for lever and sear springs.
Just takes a little time and patience.
Very easy shotgun to work on!