Many thanks
@spacecadet55, I have followed your advice. I actually found a couple more patches on other buds. Initially I trimmed out the affected areas, but eventually I removed pretty much everything above the mould patches on each branch. Not surprisingly the three patches were all within an inch from the tip, so not much was lost.
Tent rearranged with a second small 4" fan at floor level facing up, in addition to the 6" blowing downwards, but not directly towards eachother to encourage circulation.
Thank you all again for taking time out of your days folks, it us greatly appreciated. I