I downloaded the InkScape opensource software Dennis had mentioned and worked my way through how to use it. I finally came up with this design.
I have calls out to various laser cutters in town for quotes. I will most likely go with a black opaque acrylic rather than aluminum unless I can find a place that has the anodized. I don't want to be placing spray painted surfaces next to my optics. My size is for the 12" SCT so the slats are 10mm wide and spaced 10mm. The central obstruction is 10cm and the entire diameter for the full disc is 35cm.
I really like the way it turned out and can't wait to try it out!
I named it the Pavel Mask.. I thought it was a fitting name.