If money is not an issue and the exterior of the barrels are in good condition,I would go with the Teague lining,BECAUSE,you are retaining the original barrels and keeping some of the originality of the gun AND this will entail the gun going through the British Proof House and passing, which will legitimize the process and in the long run increase the desirability and value. I have had the process done to a 12 ga. Purdey HG and a friend recently had it done to a 16 ga. Purdey HG. In both cases the result was excellent.
Terry

Better to keep your mouth shut and be thought stupid,than open it and confirm.