The Hammond 1411WU chassis was perfect at 12.0 X 3.0 X 2.2 tall. Kind of expensive though considering it's just two pieces of thin bent metal.
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If you can live with less than 7 switches the 1411TU is quite a bit more compact at 10" L x 2.2" W x 1.6" H (254mm x 55.88mm x 40.64mm)

http://www.mouser.com/catalog/635/1827.pdf

http://www.almirasound.com/blog/?p=91