I had a couple of people ask for this pattern, so I have attached it for downloading as a pdf document. I have also posted a photo both in the pattern document and also here so you can see what the finished garment looks like. It is my own original creation (though I can't say for sure if someone else may have had a similar idea/pattern in the past).
UPDATE: I have tested all sizes in this pattern now and am pretty confident it will knit up as expected. I have adjusted the sleeve length and overall length in a couple of the sizes, but all other instructions are the same.
Please let me know if you have any problems with this pattern and I would also love feedback (if you think anything in the instructions needs altering/correcting) or to see photo's of any that you might knit.