In one location you find the Brotherhood T-45d Power Armor, the T-45d Power Helment, and a rare 40mm grenade launcher called Mercy. The location is inside Dead Wind Cavern, which is right below Harper's Shack and Primm Pass. However, beware, this entire location is guarded by Deathclaws. The armor itself is guarded by something called "Legendary Deathclaw" which is more than formidable.

Any chance you can throw a picture of the map location up there?

Well I won't be going there for a while