I still got some time today to quickly bike to the FabLab and cut the new legs. I didn't have orange acrylic that thin, though, so they are transparent for the prototype. The final version can of course be anything, maybe I will go for glow-in-the-dark, even!
As you can see, the new version fits perfectly -- the servos just snap in and hold tight. I used some dirty broken ones and random horns here, just to see if the fit.
The PCB should arrive within 2 weeks, I can continue with it then.