I'm not sure how the brake is held on. I can't see any evidence of threads and can't turn it by hand. On the bottom of the barrel there is a bump against the brake but if it was meant to be a spot weld it doesn't seem to have penetrated.
The bump is under the bluing and is not a rust bubble.
The gun is slightly more muzzle heavy than a full lug model 14 but I like it, helps steady the gun.
Bob