OK, after 16 days my hand is healed enough for some light slingshot making. Boy, have I missed my workshop!
I used some moor oak leftovers and some plywood, made a new variation on the Hammerhead. Slightly smaller fork tips (18mm dia, so they can be made from the single multiplex board), a slightly thicker "throat" so the pressure on the webbing between index finger and thumb is distributed better, and a "butt tail" at the rear lower end.
I feels really good in the hand, but I need to do some shooting to streamline it. Too bad there is so little daylight now, it is dark when I come home from work.