Mason had this to say in his Hurricane book:
... despite a complete absence of spare parts, most survived to see operational service in the Continuation War ... They were employed principally for interception duties owing to their lack of range, but are generally remembered by the Finnish pilots with affection, who judged them to be their best fighters until the arrival of new German aircraft. They gained a number of victories over Soviet aircraft in the early months of that war and none was ever lost in air combat.
Where on Earth did Mason get that fertilizer? Not a single Finnish source supports Mason or Chorlton.