He is not selling gear when you first meet him ("Can you sell me some gear?" is refused); his armor/weapon dealings open up only through the smithing/rivalry questline with Darrion.
Old Camp smithy — Chapter 1: The Old Camp's best blacksmith.
Gets thrown into the Old Camp's dungeons by Chapter 5 (framed over the forged weapon); you can break him out.
Quests Stone takes part in across Gothic 1 Remake.
Items Stone carries in Gothic 1 Remake.
8
You: I need armor.
Stone: So Thorus gave you the Red, eh? Congratulations.
Stone: Another man puttin' his head on the block for Gomez ...
Stone: Well, all the same to me. Here, take this armor and this sword. Welcome to the warders.
You: You're the blacksmith, aren't you?
Stone: That's right.
You: Can you sell me some gear? Armor and weapons?
Stone: Skip sells the weapons and I handle the armor.
Stone: That said, I only sell to warders, and you ain't one. You're gonna have to get some from elsewhere.