Confidence: I'm as sure as I can be.
Notes: Hmmmm. This still looks to me most like L. brevipilosum, the other most likely ID being L. niveum, which is the L. brevipilosum equivalent on Oak. That looks like a Beech bud-scale adhering to the wood, but I agree with the comment below that this is not so likely in Hayley Wood. Consequently the balance of probability moves towards L. niveum. Normally, of course, it would be checked with a microscope, when the two species can be told apart instantly. Neither species is entirely host-specific, and L. brevipilosum does, sometimes, occur on Oak, so "Lachnum sp." now seems the safest ID. I still really think it's L. brevipilosum though!