29(1)For the purpose of determining under this Schedule whether any property is a person's trading stock anything which—
(a)is used by a person ("the contractor") in carrying out, or results from the carrying out by him of, a contract for the manufacture, preparation or construction of any property ; and
(b)by virtue of a provision in the contract or of any rule of law vests in the other party to the contract before the contract has been fully performed by the contractor;
shall, until the contract has been so performed, be treated as belonging to the contractor, and, subject to sub-paragraph (2) below, as not belonging to the other party.
(2)Where the value of any property treated as belonging to the contractor by virtue of sub-paragraph (1) above falls to be reduced under paragraph 28(4) above by reference to payments made by the other party, sub-paragraph (1) above shall not preclude the property being treated, at a value equal to the payments, as belonging to the other party.
(3)For the purpose of determining under this Schedule whether any property is a person's trading stock any goods which—
(a)have been sold to a person subject to a condition reserving ownership to the seller pending full payment by that person ; but
(b)are treated in the accounts of the seller as sold and in the accounts of the person mentioned in paragraph (a) above as bought,
shall be treated as belonging to that person and not to the seller.