So I saw the Rambini Video, and made my first Slingshot in ~10 Years!

made from some plywood I had around, measures in at 9.5mm
After using it with some 8mm steel balls, I decided to try some larger and heavier pebbles - which turned out to be a mistake:
But, not being one to give up easily, I decided to try again with some Aluminium I still had, 5mm. Unfortunately I only had a long strip which was 8cm wide, so I had to scale the original down another 10%.

Another thing that bothered my was fiddling the Tubes (Dankung 1843 btw) in the divot on the Arms, which is why I decided to punch a hole in this version. It's working well for me and now.
So thanks for the Inspiration Jörg!