21(1)
Subject to this Act, where goods are sold by a person who is not their owner, and who does not sell them under the authority or with the consent of the owner, the buyer acquires no better title to the goods than the seller had, unless the owner of the goods is by his conduct precluded from denying the seller's authority to sell.
21(2)
Nothing in this Act affects—
(a) the provisions of the Factors Acts or any enactment enabling the apparent owner of goods to dispose of them as if he were their true owner;
(b) the validity of any contract of sale under any special common law or statutory power of sale or under the order of a court of competent jurisdiction.