before you make a pistol into a rifle check with your state, county and town laws to make sure you are not breaking some law, Some places have stupid and or strange laws the feds have no troubles with making a pistol into a rifle and then converting it back to pistol.
If you have the shoulder stock you have better have a barrel over 16" to go with it or have proof that it has been sent out for repair and will be returned to you.
If for some reason they find your frame and shoulder stock and all short barrels with no indications of a rifle barrel they will assume you are making a short barrels rifle which is a federal offense.
All contender barrels with the exception of the armor alloy will interchange with contender frames with little troubles, but you will need different for-ends
all encore barrels will work on all encore frames you will need a pistol for-end a rifle for-end black powder for-end, a shotgun for-end
everything but the frame it's self can be shipped person to person and via the us postal service. frames must go UPS or fed ex next day air for private sales it has to go to FFl but for repair it can go right to the repair shop and back to you and your address.