Here is one from truck and car shop.
http://www.truckandcarshop.com/4759.htmlDUAL RESERVOIR MASTER CYLINDERMOUNTING BRACKET KITS
47-09423 47-55 1st. . . . . . . $ 79.00 kit
55-09424 55-59 . . . . . . . . . . .$ 79.00 kit
you can look at their catalog to see the other brake parts
and nice ride hope my 1956 looks that way some day.