The spool rack on the top was a last minute addition after I realized that the 30" depth of the table plus the wood frame wasn't enough to put spools inside with the printer.
I didn't do a great job of sealing things up - I'm relying on the negative pressure to keep the fumes from escaping significantly. If that doesn't work, I'll seal things up better.
I will probably build a plexi door for the front eventually so that I can see in. Right now I have a webcam attached to the frame so that I can keep an eye on what's going on in there.