Aperture blades and look...

[rippo]

seems to me you could just make your own waterhouse style stops and put them over the front of the lens. perfectly round, no pesky blades to make your bokeh pointy.

[Paul Fitzgerald]

"seems to me you could just make your own waterhouse style stops and put them over the front of the lens. perfectly round, no pesky blades to make your bokeh pointy."

Wish it was that easy but that would only vignette the image.

Hate me, hate yourself for missing it:

Doppel-Amatar 250mm