Not necessarily. Could have been an attempt at removal of a burr around the hole in the hammer nose bushing. (sometimes caused by the hammer nose) Hard to say without a close inspection. The staking ring around the bushing looks in tact and undisturbed in the photograph.
Looks like some incidental B/C gap contact on the front face of the cylinder at one point, perhaps due to end shake on the cylinder or the yoke. Also the edge or perimeter of the shroud on the entry (left) side of the cylinder opening of the gun appears to have been stoned or filed. May just be the lighting.
By the looks of the turn ring, the cylinder stop should have quite a lot of wear on top of the ball, resulting in the creation of a "flat" spot, due to wear. Can't see it though, so this is pure speculation.