It is a really nice image Greg. The trouble is with 17'' of aperture the bright stars are massively overexposed. You are a bit better off at f/6.8 as compared to f/10 by about a factor of four in the ratio of nebula brightness compared to star brightness.
Sharpening massively over exposed stars is a waste of time. What you need to do is use short exposures to delineate the brighter stars and then blend by HDR.
Here is an example of what HDR can do for bright star sizes. 600k
http://d1355990.i49.quadrahosting.co..._10/hdrm42.gif
Here is your image compared with the same area taken with the 300mm lens 1.6MB
http://d1355990.i49.quadrahosting.co...10_10/grb1.gif
Note my bright stars are at about the same size as yours!
Bert