That's a beauty Geoff, always reminded me of
a marble (we called'em Snakies) and I really like the starfield in this case too
It's one of my favourite PN's actually, I hit it about 7 years ago myself with my 12" F3.8 and have always loved it. If you hit it with some really good exposure time, there is a newly discovered and actually quite a substantial, halo around it too
...actually, there were hints of the halo in my final image, so had I gone deeper myself back then (Feb 2014), it would have been my discovery/confirmation
Mike