I needed a very specific shade for a vintage Danish scissor lamp, and discovered a wonderful online resource-- Fenchel Shades.
You can customize every variable (all dimensions, material, color, fitter type & fitter placement), their service is fast & efficient, and they're also insanely affordable (my 14" X 8" custom shade cost all of $30).
http://www.fenchelshades.com/
I've seen their site!
I haven't ordered from them because i haven't had a need to yet, but I was very impressed with the range of dimensions you can choose from. My daughter needs a shade that is 5" diameter and 30" long, or something weird like that, and they were the only place that came even close.
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