After endless hours of masking, finally got her primed.
Painting process on the underside.
Started with a heavy handed pre-shading with tamya neutral grey
Looks pretty grim. Then took highly thinned neutral grey and mottled ignoring the panel lines. Did the same with diluted white, lightening some panels more than others.
Got it to lhis
Close upon the port wing
Then multiple coats of xf 23 with a tad of white, highly thinned
I've left it a bit stark in case varnish coats knock it back. Although one more thin coat of xf 23 might be in order, especially on the flaps