On the quest Boulder City Showdown where you have to go and rescue the two NCR soldiers by either negotiation, stealth, or brute force, I killed all of the Great Khans, and while looting I decided to fast-travel out to go sell off all my excess loot, then come back to finish the quest. But when I came back all the bodies disappeared, and the quest item I was supposed to loot off of a dead Khan has gone with them. Does anyone know a possible fix for this? If not, would anyone happen to know the base ID for this quest, so I can use the resetquest command in the console and redo this thing?

Any help would be appreciated.