Look for "Super cheap Bahtinov mask cut for you. Choose from MDF or Acrylic" in iceinspace classifieds. I think this link may work
http://www.iceinspace.com.au/forum/s...light=bahtinov
Then use a program called bahtinov grabber (free).
http://www.njnoordhoek.com/?p=330#comments
I have 2 of these and they are sweet! I got the acrylic ones and attached 2 green wall plugs to each to hang them off the scopes. Take your measurements carefully for the sizes, but once you have them centering them is not critical. Don't forget to remove them before slewing!!! hahaha done this!
Mark.