Very nice, low R prefix. I've got R71XX. A buddy gave it to me after I cleaned it and a 66-2 up for him. He had inherited both guns from his father and after shooting up all the old ammo, he looked at the barrels and thought they were ruined. He was so happy to have the 66-2 "fixed" that He graciously gave me the 60. The funny thing was I had been looking for that very gun for nearly five years without any luck. Meanwhile this one was hiding in his attic.
Here's what the barrel looked like before I used the Lewis Lead Remover on it. It cleaned up just fine.