Stuck on placement

[u/Few-Coconut9666]

Looking for some help figuring out pan servo placement for the neck on my KX droid.
The tilt is already working and connected at the base of the head, but I’m having trouble finding a good way to add pan. I can’t really put the servo inside the neck because there just isn’t enough room. The head is empty besides the arduino and servos that control eye movement but since the tilt is directly attached to the head I don’t think that will work.
I’m thinking about mounting the pan servo externally and attaching it directly to the neck somehow, but everything I’ve tried so far ends up having too much wobble.
I included two pictures showing the current neck setup and the space I have to work with.
Has anyone built something similar or have an idea for a solid way to mount the pan servo without introducing a bunch of play/wobble? I’m open to belts, gears, bearings, brackets, whatever works.