Good deal then, you already removed it. Yeh, I wondered about my wire under the fillscrew too, at first, until I had to remove it to fill it. Lightbulb lol. It's hilarious how stumped we can be over such minor details. I still laugh at myself for feeling overwhelmed with my first eGo kit. lol
You have to buy the Food Grade (304) or the Corrosion resistant (316). Either one should work. http://www.mcmaster.com/#wire-mesh-screens/=j3ye07 and even eBay has it. But I would refrain until you know exactly what to get. Shoot, one sheet will last you a year or more! Also, Jim has it on his site, plus you get free mesh when you order a DID from him. (not every genesis comes with wire and mesh, but the DID sure does. Jim's a great vendor!!!)
Safest bet for now, is to get extra from Jim though. He also has clear tanks,wire, and spare nuts and posts and stuff. He's on the ball, that guy!
I luckily started with the regular sized DID and was even luckier to nail it my first ever try. After hearing your tale, I'll start recommending the regular sized DID's for first timers. What a tale eh!
Thanks for the Thanks you've given, & it was my pleasure to help you out. I'm just happy that you've got it going.