They have a #5 but could not find a #3, I would much prefer a retaining ring vs a flange if anyone has one of those. I know they were made at some point as I just sold an lens with an Acme shutter that had a ring not a flange.
I've got one I'll sell you for $100 and throw in the shutter and lens for free! =]
Ilex 215mm in Acme #3 with ring, not flange. I was joking at first, but I really don't need it. I'm open to selling it if you need this.