Thanks, I love the industrial look of it too! I started with a piece of 3/16 inch steel sheet metal (not stainless mind you, this thing's gonna rust

). I'm not exactly sure on the thickness, it's probably exaggerated a bit, I salvaged it from the recycle bin at the local metal workshop, and it certainly felt pretty hefty while I was working on it
I cut the outside using a jigsaw. Then drilled holes big enough to get the jigsaw through and routed the bridge and both pickups. This was so goddamned tricky. Those weird little bumps on the jazzmaster pickup were so hard to cut using the jigsaw...
Because it was pretty bent out of shape at this point, I hammered it back into shape on the anvil. Then I drilled the rest of the holes and tried to bevel the edges a bit using a bench grinder. Then polished it up with a brush attachment for the grinder (that's how it got that weird directional look).