That is not at all bad for a digiscoped shot, especially under those lighting conditions. I have made a couple of adjustments in Photoshop: altered "shadows & highlights" to bring out more detail on the bird's back, increased colour saturation, brightness and contrast slightly, removed some noise with "Neat Image", and slightly sharpened.
There are limits to what you can do to a JPEG (as opposed to a RAW or TIFF image) that has already been "cooked".
When I was digiscoping with my Swaro 'scope and Coolpix 4500 I had both the Swaro DCA (just a tube connecting camera to scope) and that ridiculously overpriced DCB (the swing-away digital camera base) - I gave up with both. I now carry a Panasonic DMC-FX9 for which I have made an adapter (a cut down pill box of the appropriate diameter) which slides over the extended camera lens and I then just hold it up to the scope if I want to take a "record" shot - it produces better images than the Coolpix with Swaro adapters ever did, and takes seconds to set up.