Thanks for posting this, I was about to design one for my YN-560iii when I thought to search for it first. I wasn't sure if it would fit so I loaded the stl file up in Sketchup and took measurements, it seemed like it would still fit and it did, perfectly! My assumption is that it would fit the YN-560ii as well.
Printed in 3hrs on a PrintrBot Simple Metal with 0.4mm layer height and 2 surface layers. I had 25% honeycomb infill set but I'm pretty sure that wouldn't matter since it's all just perimeters.
My only suggestion would be to flip the model on the y axis by 180º so that people don't accidentally print it the wrong way up, I was in a rush and almost didn't notice that the "flash receiver" end was on the bottom of my bed when I first imported it.