Hello everyone, I have a used British double that I'm looking at potentially purchasing but need some help. I can't figure out what's going on with the left ball fence, on this one. Note the disk? It looks like something was cut out and repaired, but I'm not familiar enough with English doubles of this age to know if this would be something to be wary of. Any advice would be greatly appreciated. The gun is from a very reputable maker in London that would go on to helm one of the oldest and arguably best double gun makers in the city.

[Linked Image from i.imgur.com]