At the Old Camp gate he only checks why you are entering and will not train you until you join the Old Camp Shadows ("I only train warders ... until you're one of us"). His trade window and crossbow training open only after he leaves the Old Camp.
Old Camp, main gate — Chapter 1: Gate guard (a Shadow) who vets who comes in
Cavalorn's hut — Chapter 4: After Gomez has the Fire Mages murdered, Scorpio quits the Old Camp and sets up here, where he trades and teaches crossbow
Falls out with Gomez and Raven over the killing of the fire mages, takes good steel from the armoury and quits the Old Camp, relocating to Cavalorn's hut where he trades and teaches crossbow.
Items Scorpio sells in Gothic 1 Remake.
Scorpio can be found in the Old Camp (Guard).
Scorpio: Anyway. I'm done with Gomez, Raven, and the whole fucking mages. I mean, killing mages of Innos? That's asking for it.
Scorpio: Lucky for you, I snatched some good steel from the armory before I beat feet. Let me know if you need anything.
You: I want to be even better with crossbows.
Scorpio: And I'd love to help you get there. For three hundred nuggets.
You: Can you teach me something?
Scorpio: I could. I'm the best damn crossbowman in the Colony. But it'll cost you ...
You: Deal. Teach me how to handle a crossbow.
Scorpio: Okay, let's get right into it.
Scorpio: Hold the lady steady by the front and press the stock against your shoulder to keep your aim solid.
Scorpio: The first couple of days, you'll feel like your shoulder is falling off.
Scorpio: But after a week or so, it'll be hard as a rock.
Scorpio: Also, breathe. It's everything. Calm, and deep exhales and inhales - that'll ensure you hit your mark.
Scorpio: Two hundred nuggets, my friend. This ain't a charity.
Scorpio: Who by Beliar let YOU in here?
You: Thorus.
Scorpio: And what do you want?
You: I'm on my way to see Gomez. I want to join you.
Scorpio: That so? And why would Gomez be interested in someone like you?
You: The Shadows were happy with my work.
Scorpio: Huh, Shadows here, Shadows there ... we're callin' the shots in here, get that into your head. But fine, give it a try.
You: Just wanted to take a peek inside.
Scorpio: Ahh, very funny.
You: I have a delivery of swampweed for Gomez.
Scorpio: Ah, makes sense. Best bring it straight to Bartholo - he's in the main tower, the building with the two guards in front.
You: I have a message for the mages.
Scorpio: ... You're one of your messengers, then? In that case, go ahead. I don't want anything to do with that.
Scorpio: Ey! Come over here for a second, will you? Don't worry, I'm on your side.
You: Can you teach me how to fight?
Scorpio: I only train warders ... until you're one of us, find someone else.
You: Show me what you got.
Scorpio: So you're one of us now, eh? Good choice!