You've got some wrong info for Guss Tuno. I just recruited him last night.
Guss Tuno: +10 Underworld Trading Eff.; +2 Investigation Critical
Really? That's outstanding! I mean it's bad I have the info wrong, but investigation is infinitely better for smugglers, and will make armstech unbelievably good for them. I am going to confirm this right now.
Edit: Confirmed. Great!! What's even more interesting is that Guss also has Underworld Trading -- in addition to Corso! No other class in the game has double tradeskills.