Where can I get Thieves' Guild armour?

When someone gives me armour that I don't want, I sell it. So I sold my Thieves' Guild armour, and now the fence wants to upgrade my armour and I can't sell anything to her until she does.

Where can I buy more Thieves' Guild armour?

Update: Getting the armor from qasmoke didn't work. It's been many in-game days and whoever I sold the armor to has had their inventory reset.

Solution 1:

Thanks to a useful post on Yahoo! Answers, I realized there's actually three sets of Thieves Guild Armor you can spawn through the console, and the UESP is listing the wrong one. The ones you want are as follow:

player.additem 000d3ac2 1
player.additem 000d3ac3 1
player.additem 000d3ac4 1
player.additem 000d3ac5 1

I've just confirmed it working. The ones the UESP list aren't visible in inventory view (they do show up in the world, though). I suspect they're meant for NPCs, since many NPCs carry invisible-from-inventory armor. Being different armor, it won't work with Tonilia's quest.

For completeness's sake:

00036584 - Armor, NPC version
000d3ac3 - Armor, Basic version
000d3acc - Armor, Upgraded version

00036583 - Boots, NPC
000d3ac2 - Boots, Basic 
000d3acb - Boots, Upgraded

00042be9 - Glove, NPC
000d3ac4 - Glove, Basic 
000d3acd - Glove, Upgraded

00036585 - Hood, NPC
000d3ac5 - Hood, Basic 
000d3ace - Hood, Upgraded

Solution 2:

You have to buy it back from the person you sold it to.