I reread and made sure you said, "2.5-3.1" CLOSED",
yup, you did...
Since you already said you have GEC's, W&H's, etc. I assume you don't mean more slipjoints, so it gets a bit tricky, as even 2.5" knives usually come in closer to 3.5" closed, but a few fit the bill...
Now, I prefer larger blades save for a small SAK and Leatherman both on respective keychains, so I can't comment one way or the other on any of these knives, but if I was looking for a small knife, these companies all (in my expreience), make a quality product I would trust and be interested in.
Rike Hummingbird = 2.25"
Stedemon Vouking = 2.75"
CRKT Eros 2 = 3"
A.R.S. flip shank = 3.125"
Lionsteel 8210d = 3.25
Spyderco Techno = 3.45"
Spyderco One Eyed Jack = 3.5
Spyderco Chapparal = 3.6
Boker Pipsqueek = 3.65
Mcusta Bamboo: Bestech Imp & Goblin: Viper Voxnaes Lille: all = 3.75
FWIW, not having any really small knives, if I were in the market, my top picks would be the Rike & Lionsteel because they come in damasteel, the Boker in 3v, or the one eyed jack because it has a cool handle (if you play cards).