Agree with Steve (SKB). WR started sleeving guns in the late '50s or early '60s. Quite a few improvements (e.g., TIG welding) have been made over the years. Is the gun being sleeved originally damacus? If so, the reblue of the damascus breech may not exactly match the new tubes, but it can be very close.

If you have a gun sleeved in the states by Kirk Merrington, the only potential drawback is it won't be proofed.

Ken