I have a very long neck. It’s a thing that would probably have gone unnoticed my whole life (by me at least) if I didn’t play the viola. But as it is, I can’t play without a shoulder rest – a padded accessory that attaches to the back of my viola adding height to the shoulder, and making it easier for me to hold the instrument in place.
This is my favourite line of the wiki entry for shoulder rests:
Depending on body type and style of clothes, some musicians need no more than a thin sponge, a cloth or sometimes nothing at all under the instrument.
I’d love to know what article of clothing might double up as a shoulder rest, some kind of Elizabethan ruff made of Styrofoam perhaps. Anyway, what with my clothing deficiencies and peculiarly long neck, I’ve become quite a connoisseur of shoulder rests. During my teens I stuffed all manner of things in the gap between the back of my viola and my collarbone, including the sponge we used for washing the car (strapped on with an elastic band) and a mangy velvet beanbag thing. This is what I now use:
It’s fine, but for some reason I still can’t quite get comfortable when I’m playing, and I’m not sure why. It could be down to the chinrest. I thought these were much of a muchness but have been reliably informed that they vary quite a lot. Mine has particularly curved edge that locks it in under my chin so that it’s difficult to move my head around when I’m playing. This can be remedied: I could get a flatter one and have it fitted.
But, this is where I start to feel a little silly. It’s all very well customising your instrument if you’re Laurence Power, but I can’t help feeling that for someone of my standard it’s a bit like buying a harness and crampons for a stroll along the South Downs. So, until I’ve got a little bit better at playing the viola, I’m going to stay a little bit uncomfortable.

No, no! I know what you mean. But until you’re comfortable, you’ll never be Laurence Power. Get yourself sorted lady!
Did you ever get the problem sorted out? I also have a long neck, and a viola with a very wide lower bout so not every should rest will fit it. I went through a number of setups and finally tried a high chinrest (made by SAS). It solved the problem immediately.
I did actually (note to self – remember to report back on things I’ve posted about). My husband very sweetly bought me a new, much flatter chin rest made of leather. A combination of that and the Wolf shoulder rest (and probably a gradual improvement of my playing position over the past few months) seems to be working out a lot better.