or just have a one use key, three doors. Each door to its corrosponding equipment package, i.e. sg, ew, bg. newb player takes key opens door, key snaps. player then can take the apropriate gear of one of the three rooms he has unlocked. on his way out, a shelf has a couple caps, a few junks (enough to make brass knukles, oh dear what a coincidence) a pack of cigs, a beer and a knife. Welcome to the wasteland.
Anthor plausable situation (these can be all incorporated if you like for variety)
three old hereos, buried on the top of "boot hill", you with a rickity shovel (again onc use item). Dig up the "hero" you like and get the corresponding gear that accompanied him to the grave. in a crate by the fire, a few unsundry items to fiish off your newly acquisitions. Have a nice life.