Finally, buttons found, approved of, sewn on and ...voila'!
After much thought, I opted for non-green buttons. These, which I found at John Lewis, were just right - and they were reduced in price as well!
Shame about the quality of the picture...the yarn is a nice green, but my camera seems to have an adversion to green. I might try and take a picture of the jacket outdoors, but in order to do that I must wait for this strong wind that is visiting Nottingham to stop.