While checking out Nipton, on one of the memos it said that the mayor had a stash in a building between Nipton and Mojave Outpost... anyone found it? is it worth chasing?

IIRC, it's that gass station down the road from the Mojave Outpost.

I also found a dufflebag in a completely demolished house in the Nipton Rest Stop. (Not the gas station but across from where the Jackal camp is.) It had a few hundred caps, a couple of low level guns and a few assorted pre-war food items.