(1)In this Chapter “trading stock”, in relation to a trade, means anything (whether land or other property)—
(a)which is sold in the ordinary course of the trade, or
(b)which would be so sold if it were mature or its manufacture, preparation or construction were complete.
(2)It does not include—
(a)materials used in the manufacture, preparation or construction of any such thing,
(b)any services performed in the ordinary course of the trade, or
(c)any article produced, or any material used, in the performance of any such services.