Perazzi did not sleeve barrels to change choke. Silvers is probably correct in identifying your barrels as having Teague screw-in chokes. Nigel Teague was an engineer for Rolls Royce and the tolerances he achieves with his thin-wall flush mount chokes are so tight and precise that most people can't look directly down the muzzles and see the chokes with the naked eye, unless they know what to look for. Try a Teague conical wrench or a universal expanding rubber collar wrench and see if the chokes come out. You'll find the serial number of the barrels engraved on the choke tube. Teague is indeed the "Rolls Royce" of thin-wall choke systems.
