Thank you very much for the quick reply. I will absolutely heed your advice and have the barrels checked for wall thickness by someone with a lot more expertise than myself.
I've read through the FAQ and will now attempt to polish the bores with the ScotchBrite and 0000 Steel Wool method as it's what I have available.
According to the FAQ the recommended method for removing the surface rust on damascus barrels is with white chalk and gun oil. Would that be the best method to use for these barrels with fairly significant rusting or would it be best to start with something like 0000 steel wool and oil on the exterior as well or will that damage the damascus finish?