Found an interesting site today (Boats With Wheels) and got some more ideas with the dolly. As a result, I think I've got a finished design. Wife says it looks like it comes from some third world country but I take that as a compliment. Here 'tis.
Let's face it, the mast and boom are a bit of pain when it comes to getting them out of the way. Finally got a solution. I've finished the sail repairs, so I've assembled the sail, mast and boom (added a natty little Aussie flag at the top) and then roll the whole assembly up. I keep it all wrapped up using the shock chord from the tiller and the downhaul rope. Then it's up, under the shed awning out of the way on a couple of brackets I knocked up.
I've also put the rudder and centre-board together, upside down and back to back and hold them together by wrapping the sheet around them. I figure if I do this I can't forget anything when I go for a sail. Now I just have to find somewhere to store those and the oars.
Edit Jun 2016: The top of the mast, about 25 cm, poked out the side of the awning in the weather. After six years that part of the mast has rotted. Now I just have to decide whether to make do with a shorter sail or extend the mast back to the original size. Mike Storer designed the layout of the mast, sail and boat to be nicely 'tuned' so things will all be a little bit off if I change things. Also have to remake the sail as that has rotted away as well. Things to consider, things to do.