if it's on an npc in a gaurded town then that is a real dick move. This means you need a specialized thief alt to get it... which means alot of people prolly wont get to participate even if they find it.
Or he simply sold them to an npc trader.
and its too much places for hide items in each city, so its abit impossible to find gauss, give us few tips, maybe story about place from fo 1 or fo 2, or speak like mad black man in malamute, that giving quest.
its also quite impossible to find the "g" key on the keyboard too