Monster Mouth Headphone Holder- plus audio jack

I don't use headphones with 1/4 inch phono jacks, but I do use a computer that sits in an awkward position for plugging headphones in and out.
With a cheap audio extender (on sale for USD 1.99 at Aldi) I modified philbarrenger's design to not only hold the headphones, but also hold the adapter socket.

The audio adapter has a barrel that is about 8.5mm in diameter, with a cable that is 3.4mm in diameter with some compliance. I bored a 10mm hole in place of the 1/4 inch phono 'eye' then creat