In reply to Simon Caldwell:
I can shed some light on it!
It's been dismantled because it was getting very dilapidated. Coniston MRT is in the process of replacing it with a nice new, but still blue box. It's made and is aimed to be installed sometime in October.
I understand the wood was originally stacked but it's possible that the unusually high winds (even for Dow!) for the time of year has scattered it all a bit. Disposal of that is also planned for the near future.
It's (sort of) part of Coniston MRTs 70th anniversary celebration!