Thanks Brino!Lee Valley sells brass shim stock, six different thicknesses by the 6"x100"roll, or a sampler pack with 2"x6" strips of all six thicknesses.
http://www.leevalley.com/en/wood/page.aspx?p=40946&cat=1,43456,43407
I always try to keep a sample pack on hand.
-brino