Dad's Wasteland Outfit

This is the same jumpsuit you see your father wearing just after exiting the Tranquility Lane Tranquility Lounger in Vault 112. It is identical to the Vault 101 Utility Jumpsuit except that the suit has black boots, instead of sneakers. This outfit is possibly just Jamse's vault 101 lab outfit minus the coat.

Location
One way to get this item is to reverse pickpocket an outfit with more protection onto your dad either when he is talking with Doctor Li, or while he is standing in the Jefferson Memorial Rotunda. After that leave the room and return, your father should be wearing whatever you put on him, as long as it has more protection. After that pickpocket it off of him, only if you don't mind the slight Karma loss.

Another way to get this outfit is by standing directly in front of the airlock door in the Memorial Rotunda right after his death, so that you are right in front to your dad's corpse, then hold LB/L3 and slowly rotate the camera around till you see "Search Dad" on the the screen. This only works if his body fell close to the door. You can also do the same with Colonel Autumn, who at the time will have Energy Cells, Ammo, Colonel Autumn's Uniform, and Colonel Autumn's 10mm Pistol.

Also, if you're quick enough you can pass through the airlock door to obtain everyones stuff in the room. But there is no way out.