@AstroFin Cheers - it exceeded expectations for sure.
The original image was quite noisy with what I understand to be 'walking noise' which I've now read up on and it looks like I can mitigate by dithering.
I don't think it's poor polar alignment or bad tracking because as you said, the stars are perfectly round.
Also, I'm interested to know what people think about 180 x 30 sec -vs- let's say 90 x 60 sec. Assuming the tracking and alignment are good, do the longer exposures actually help.
Part of me wants to capture the same target again with dithering to see what difference it makes, but I might just do a different target instead and come back to this one.