Nice work, Paul! It's a cool object and you've captured and processed it very well.
I first saw the Oiii halo faintly in an image by Martin Pugh. I have 75 hours on this object from last year that I should probably finish processing. Unfortunately, I wasn't able to get anywhere near the detail in the Oiii halo that Don Goldman had in his inverted image (and no other image that I've seen has come close either.) I think that with his aperture and image scale he's able to take read noise limited subs in a manageable time which is something that those of us with 12" scopes can only dream about in narrowband. Still, it's fun to try
Cheers,
Rick.