Hi Mark
Nice widefield .... you don't always need to use such tools as curves, levels etc etc ... it depends on the image.
A simple way to improve images sometimes is to make a duplicate layer and then apply it as a "soft light" in your layers menu ... flatten the image and then adjust colour balance. I did this with your image ....
colour balance settings as follows ...
midtones blue +5
highlights red+5
shadows green+5
Here's the result ............
