Following the suggestion from Greg Bradley I have downloaded Microsoft ICE and gave it a run on my Winter Milky Way image. I'm quite impressed I have to say with its capabilities.
With this version I did not try and level off the horizon and just left it pretty well as it came out of the stitching process using the stereographic projection option in MS ICE.
The 'fish eye' presentation is a bit odd but the benefit is that I can squeeze more data in including Jupiter and the top of the image which I had to crop out previously. There are now three planets in the image and many deep sky objects scattered across the plane of the Milky Way. Feel free to go DSO and planet hunting. All good fun to be sure
Link to image on Astrobin is here.
Click on image in Astrobin of larger resolution.