Canvas bag on the front nearside wing? If it was a bag probably an owner fantasy embellishment, like many preserved MVs suffer from. There should be two webbing straps there for a cam net.
On the other side there was sometimes a supplementary generator for FFW & FFR versions, as the 25A output from the engine gen was inadequate for that role. Sometimes owners will fit them on APCs just because its another bit of stuff to have there.
Rear wings, well no formal rules for what went in them. Presumably things like starting handle, intervehicle jump leads, rope etc Anyway that's what I keep in mine.