Many thanks for all of your comments, really much appreciated

The three piece top wing! - Thank goodness there's no dihedral to complicate it. Spent some time lining the pieces up against a metal ruler.
Interesting, about the Brumowski scheme. I don't think I'll be doing any of my planned set in it, mainly because of the difficulty of rendering the little yellow curlicues in this scale. I think someone did produce a decal sheet of them a while ago, but, never mind.
I eventually want to do a 253 (as seen in the Osprey book) with its wings covered in that psychedelic sworl fabric, I've picked up a nice sheet of it from Aviattic.
Thanks again
Mark