Crazy Wolfgang

Crazy Wolfgang is an eccentric Caravan Merchant specializing in the sale of junk. His inventory includes random bits and pieces used for constructing weapons, and also a copy of Rock-It Launcher schematics. Crazy Wolfgang's local inventory can be found in Uncle Roe's house in the first metal box in the corner. The key can be recovered from his corpse.

Unmarked Quest: Merchant Empire
Initially, his repair skill is at 15%, but after talking to Uncle Roe for further Caravan Merchant investment, his inventory will expand, and his repair skill jumps to a maximum of 75, the highest in the game (allowing him to repair items to a max of 85%). If you reverse pickpocket a near fully repaired +5 Repair article of clothing he can repair up to 88%. Note that after the second investment he also sells Pre-War Books, however these books have purple covers and cannot be traded in at Arlington Library. After the second investment, he rewards you with 5-7 Stealth Boys, depending on your level.

Location
Crazy Wolfgang appears outside of frequent stops every time you fast travel to that location, go through a loading screen to that location, or wait at the site for a few hours. A good way to find him is to fast travel to Rivet City and go down the metal stairs. If he isn't there, wait for one or two hours so a merchant spawns. If the merchant isn't Crazy Wolfgang, wait for one or two hours again. Repeat until you get him to spawn.

Trivia
Agatha includes a shout out to her "old friend" Crazy Wolfgang in her broadcast, saying "No one can scour the Wasteland and find such oddities as you".

Bugs
Usually, if you successfully pickpocket Wolfgang and steal his Rock-It Launcher schematics, you can then immediately buy another from him, giving you two schematics for the price of one.