It's going to be useful to get before- and after- winter pictures of this shed.
I suspect pallet wood with its rodenticides may hold up better than MDF.
It's been illegal to treat pallets with Methyl Bromide in the eu since 2005. All white pallets are stamped with a manufacturer's mark on at least one of the corner blocks, look for "HT" among the other coding, this stands for "Heat Treated" and means it is safe to handle or burn.
I will post some pics as and when the job progresses.