Fred'k Williams was a good medium sized Birmingham maker for over 100 years, their quality was consistently good within the price class of the individual gun. Most of their production was for the trade, guns with their own name are not common, reflective of this fact. This is not another tired old Belgian clunker and if otherwise sound may well be worth salvaging.
Properly trained journeyman gunsmiths use a special shotgun barrel dent remover that is positioned inside the bore under the dent and hydraulically expands against the dent to raise it while lightly peening the outside edges of the dent. They will not attempt sharp dents or those showing a beginning crack, or in badly pitted or dangerously thin barrels. They usually charge $40-50 per dent and the interior will be near perfect, the exterior may barely show. When properly done and finished this method will show as a new gun and is the only method recommended for fine quality guns, old or new. As mentioned, an acceptable job can usually be accomplished by forcing a tapered plug or series of increasingly sized plugs past the barrel obstruction caused by the dent. It is vital that the plug contact as much of the interior barrel wall opposite the dent as possible. Because it doesn't require specialized tools and the plugs can be made by anyone with a lathe this method is popular with hobbiests and gunsmiths who don't do a lot of shotgun work. This method usually leaves some slight noticeable marking both inside and outside but the cost to customer should be considerably less. J.