This is a slight tweak to David Randolph's excellent 3mm hood and side panels:
The only major change is that I extended the edges of the 45deg piece so there was less gap between where it meets with the top cut piece and the front cut piece.
It fits great and there is only just a tiny bit of sagging on the 45deg piece. David opted to have a gap between these pieces to help dissipate some of the heat.
If you want what I am using, I made the ponoko design public:
These are the exact same files I used to cut the pieces you see in the pic.
I have not updated the design to move the top right bolt on the right side window (when facing the front of the replicator) to the center. Some have reported the side bolt interfering with the gantry and extruder heads when homing them. I'm using these printable clips:
And I haven't noticed a collision.
I've uploaded an SVG file I created in illustrator. Let me know if it gives you trouble or you would like an alternative format.
Update 6/23/2012 :
It turns out that both clips on the right side window are hitting the gantry or some component hanging off of it (like the wires). This is enough to prevent the gantry from easily homing.
For the time being, I've removed the two clips on the top of the right window. A piece of tape is holding the top in place until I can come up with an alternative. My next step is to shrink the thickness of the clips slightly. If this doesn't work, I'll probably update the plans and print a new window with the clip/screw hole in a different location. I'm not sure if the center of the window would provide obstruction, but it is better than the current positions.