A little more progress:
I've brush-painted the grey undersurfaces, and green uppers. Three coats of grey and four of the green...
and
A few little touch-ups on some of the lines, and then gloss varnish to prepare for the decals.
I know I still need to paint the details (exhausts, undercarriage, guns, pitot, aerial, prop blade tips, etc.), but at least it's progress.
I must admit that, even though there are a lot of issues with fit and flash, it's not bad. It looks OK to me, and that's all I ask for.