The composition is good and the choice of focal length works well. I would adjust the dark areas to the right, where the vanes start to disappear into the background, which also suffers a little from being too dark.
Personally, I would also ease off on the contrast slightly as I wonder if the colours are not a bit too intense?
Basically a sound image though, and I hope you don't think I'm being too harsh with it!
I agree with John about the dark areas, they could take some lightening up.
I like the intensity of the colours though, and think if you could lighten those blades the red with the blue and the green would really be quite striking.
That little patch of yellowing grass in the bottom left I do find a bit distracting, but I think you'd need to clone it out to do anything about that, as your crop is great.
It's a decent record of the windmill - colours and exposure are fine.
I find it a bit 'static' though, ie there's not much going on in the photo to hold my attention for very long.
It is heartwarming to see this beautiful structure fully restored back to its former glory and I think you have done it proud; i personally would have taken the sails more full on and maybe lightened up some areas, but otherwise a perfect record shot, well done
"I look up to Pammie....especially when I am grovelling to her to let me win!!"
I take all of your comments on board and I am going to revisit this windpump and give it another go, rather than mess around in photoshop Isn't it wonderful how you can look at an image and be quite pleased with it until another persons eye spots something and suddenly you want to go back and try again? I call that a result, with a lot of luck and some effort maybe this comment/critique lark will improve our photography?