Depends on what's wrong with it. You say "shot out", so if it's just the bore, you could re-line it pretty inexpensively. Gunsmiths used to do this kind of thing a lot, but they are getting harder to find. There is a place here in the USA called "Redman's" (
http://www.redmansrifling.com/liners.htm) that all of the Cowboy Action Shooter who want to use original guns use. They do Mauser Broomhandles too, I hear, so they should be able to handle your problem as well. May cost a couple hundred, plus shipping, but I doubt you will find an original barrel very easily.
All I can say is make sure that whoever works on a job like this knows what he is doing, mistakes on relining jobs are hard to fix.
H