medic15al-
Your post is a little confusing... at least to me it is. I have 2 Cimarron Custer 7.5" (Old Model Frame) cylinders are beveled; the 2 Uberti Cattlemen I have with 4.75" barrels are Old Model frames and their cylinders are beveled. My other two Uberti revolvers are Taylor & Co., Smoke Wagons 5.5" barrels (Pre War Models) their cylinders are beveled. The only Pietta's I have are 2 1860 Army that have been converted using Kirst Konverters, their cylinders are not beveled. I have never seen a two piece cylinder bushing...
What you are calling a Cylinder Bushing is a Base Pin Bushing that slides into the Cylinder and there is a Base Pin that slides into the revolvers main frame into the Base Pin which holds the cylinder in place. If the two pieces you are referring to is the above then yes it is two piece... the Cylinder Bushing and the Base Pin. If is is not, then I am lost in regards to your post. Look to the schematic that came with the revolver and it will tell you the name of the parts. Pre-War models have a Base Pin Screw/Spring/Nut, Old Model Frames (sometimes called Black Powder Models) do not have this, they have a Base Pin Screw that keeps the Base Pin in place.