One solution could be to make your own buttons which isn’t as difficult as you think. Dorset buttons are one option and have a rich heritage. As the name suggests there was quite a large industry making these buttons in the county of Dorset. At its height, the production of these buttons gave jobs to 4000 people across East Dorset. They were popular for over two hundred years from the 17th Century onwards. Instead of using labour in a factory, the button makers worked from home which meant they could fit their production around working in the fields. In 1851 at the Great Exhibition a button making machine was demonstrated which was the beginning of the end for this heritage craft. The WI and various other organisations have kept the tradition alive and today one of the major proponents of this largely unknown craft is called Jen Best from Beaker Button.
There is a fantastic tutorial for the basic Crosswheel button here. It will probably take you a couple of attempts before you get the technique but then you will be away. And they are really addictive.
We used our Fine Merino 4-ply and some washers that we bought at B&Q but you can find metal rings quite easily on eBay. Because our yarn is worsted spun and the Merino fibre is so fine, the buttons turn out really well, as you can see.
So now you never need worry about having the perfect buttons for your Yarn Stories project and you will have learned a new craft as well.