Thanks for the compliments everyone. I'm overwhelmed. TA!
I just provisionally cast 50 stitches, then worked in chart for sthg like 4 or 5 repeats, then started to increase one at each side for 2 repeats of the 10 row chart.
Therefore I had increased by 40 stitches, I then joined and worked in the round for two repeats of the chart.
Then I k2 all around.
Then worked 10 rows in 2x2 rib in cream, followed by two rows in 2x2 rib. Then one last row in 2x2 and then cast off
Then picked up the provisional cast on stitches and increased as for the other side and completed the sleeve as for the other side.
I've probably not written that very well, but just to show it wasn't too difficult - if you can understand my scribbles.
The link to the chart I used is as follows:
However I added an extra blue stitch in top right corner to complete the pattern.