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 a Schematics for a Rock-It Launcher. He can repair up to 15%, but after talking to Uncle Roe for further Caravan Merchant investment, his repair skill jumps to a maximum of 75, the highest in the game. Crazy Wolfgang can sometimes be found just outside Megaton and any other place Caravan Merchant stops.

If you resurrect Wolfgang after the investment, he will still have the expanded inventory but not the improved repair skill. This can be corrected by clicking on Wolfgang with the console active and typing "setav repair 75". Uncle Roe will still consider the merchant dead in his conversation with you.

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.

Once you full invest into his shop he will sell Pre-War Books.

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".