Tormentil...

... is the name of the mystery flower. Thanks to Sean for the tip. The only puzzling thing is it has too many petals, but the leaves are definitely right. A hybrid perhaps? Here it is again:
I wasn't around last weekend, hence the lack of new photos from the wood. We did pop up briefly on Monday night, but that was just to take some materials for track repair. We'll be doing this again on Thursday I think. We're trying to fill in some of the tractor ruts in the wood so that when we eventually get our land rover we'll be able to drive right through!

Mike