Thanks Geo and Wayne.
This one is the period before the full yellow I.D. markings Wayne, and only lasted around 10 to 14 days approximately, before the noses got the yellow, and the yellow full rudders etc, although of course there were exceptions and 'hybrids', with the earlier style continuing, on some aircraft, into mid-September.
As I seem to have got 'stuck in' on the 'Gustav', I have yet to do the couple of areas to be re-touched, and add the antenna wire, but I should get that done very soon.