I use a couple of pieces of 16 Ga. (about 1/16" thick) bent into an "L" shape. A little bit of electrical tape to protect the guitar top. You can bend that stuff with just a vice. A better bet would be to get 1 1/2" square tubing (double check the inside clearance) and drill holes in opposite sides. Use a Dremel to open one hole into a slot. If you can buy just the material you need should be well under 10 dollars.