The front wasn't as fine as I'd thought, as a section had a rippled finish from some kitchen towel I'd used to rest the front on (on wooden blocks) when spraying the rear. When I discovered this (after a week of it hanging) i sanded it down, but this then exposed the lighter paint so I got a flat but patchy area. And there were a few small paint bubble holes on the rear.
So I touched those up with a paintbrush, left it another week and had ago at sanding those areas down yesterday. Back was fine, but the front still showed ripples and then a slight 'tide mark' around the sanding area where I'd gone down a paint layer.
This paint is very changeable in colour depending on how much of the white settles out and then gets re-included when mixing, despite a jolly good stir beforehand.
So out came the spray gun and more coats went on yesterday. It was a great day for spraying, about 22°C and still, so I applied 4 good coats, which will now dry for a week before I do another initial sand and hopefully it sands OK, after which it will be left for another couple of weeks before final sanding and polishing. It's got far more coats on that I like, so I'm hoping it dries OK, as it has been quite a while since the first new coats went on and it's had a lot of sanding back flat in the meantime.