ok, how bout this (brainstorming):
22 rifle, call it a 'Small Game rifle' or 'plinking rifle'. It replaces the hunting rifle from FO3 and the name has a more 'yankee-east' feel than 'varmit' rifle. I would expect a wood stocked bolt action with basic open sights, dovetailed for adding a scope mod later. It would not be silenced except as a mod.
22 revolver replaces the 32 revolver. It would not be silenced, except as a mod. (gun nut mode: There are a lot of '32' calibers in rifles, but none of the 32 revolver rounds really 'made it' in rifles, they are all rifle specific rounds; also 32 pistols are much less popular in the US except as holdout/small concealed guns).
In regards to the shotgun, if you wanted to keep it on unique ammo there's always 16 gauge, which was generally more popular in the east than the west anyway.
(Ironically, the over/under shotgun is also more of a eastern gun than western one, but oh well...)