Where, in any proceeding under this Act, the Crofters Commission is empowered to pronounce an order, the landlord and the crofter may agree to accept the decision of a sole arbiter mutually chosen instead of the decision of the Crofters Commission, and in that case any order pronounced by such sole arbiter shall, when recorded in the “Crofters Holdings Book” along with the agreement to accept his decision, be as effectual to all intents and purposes as an order of the Crofters Commission; and all regulations applicable to the Crofters Commission, and to the orders pronounced by them, shall apply to any sole arbiter and the orders pronounced by him.