I've done a few conversions using CZ barrels (AA S200 barrels) these have been reported back as "tack drivers" by the owners, time wise, they do take a bit of work to fit and finish, most lads have been happy to take them polished and cold blued for the section that fits between the breech and the barrel supports which is turned down from 15odd mm to 14mm, the last barrel support area I have made a tighter fit so there is even less clearance and room to move.
the remainder of the barrel is left full diameter and the shroud modified to fit. once done, no going back. then again, no real need to.
You gotta ask yourself if it's worth £250 to try it ??