i'm wondering if you might bebetter to go 'no dig' Fraser, by raising your veg. garden up above ground level. It seems a big expense and a big tool for such a small plot. Then you could fill up with compost and you'd not need to dig your plot over every year.

Just joining in to see any replies

I haven't dug for 25 years! I started off double-digging and then realised that all I was doing was mixing topsoil and subsoil and killing worms. Best to let the worms get on with what they do best. They take organic matter (compost, mulch, leaves etc down into the soil, and turn them into good humus.
All you need to do is cover the soil. When you are not growing anything, cover it with carpet or cardboard (wetted) and when you want to sow seeds just rake the top a little. As long as a crop is growing it is fine, you can mulch around the crop if you want (I do - I hate weeding!) Then once the crop is out - cover the siol again, with compost, mulch or carpet again.
If you have a problematic soil: - stony - get as many stones out as possible and then make raised beds, add compost and plant stump-rooted carrots etc. Or longer ones will fork when they hit stones.
A heavy clay soil will benefit from oodles of added compost and you can add grit/sand as well, again raised beds give a good depth for growing without trying to break up hard clay.
A thin soil that drains too quick or a poor soil with no fertility can also be made so much better by raised beds filled with compost and manure (well-rotted) then the soil will hold moisture better and not dry out. Again, add mulch.
There is great pleasure in gardening, but not much pleasure on heavy digging!
I don't like tillers etc because unless your plot is totally weed free - all you do is break up weed roots and they turn into more plants! More weeds.