Hi Ken,
No one seems to be jumping at this one.
Your find looks to have a certain similarity with this: -
Small White Crust for ID.
Certainly comparing with the edges of the example in my pics. - Although your photo looks to have been taken at closer range/higher magnification.
Unfortunately, as can be seen, my find didn't get very far with identification either, - just not enough info on the pics. (I'm still no nearer with that one 12 months on).
Regards,
Mike.