How many blades in a Kodak Supermatic/203 Ektar?

Round aperture or hexagonal?

Frank, while you're waiting for someone with a 203 to answer, the Supermatic that my 127 Ektar is mounted in has a pentagonal opening with very slightly rounded sides.

Frank,

I just bought one here and it has 5 blades and the aperture is a pentagram as Oren described.

Pentagon.