Frames on vintage double guns were originally case hardened at the factories for a reason.

Annealing brings the steel back to its pre-hardened softness. Shooting an annealed gun will likely lead to premature wear on the bearing surfaces and cause the action to go loose before its time. Surface dents, dings and scratches are also more likely to occur. For those who've ever filed or sanded hardened and annealed steel, the difference between the two is remarkable. If you intend to shoot it, have it rehardened. If you don't like case colors, they can easily be brushed off to enhance the engraving.

"Life is too short to hunt with an ugly gun".