s 20 Inchoate instruments
20.—(1) Where a simple signature on a blank stamped paper is delivered by the signer in order that it may be converted into a bill, it operates as prima facie authority to fill it up as a complete bill for any amount the stamp will cover, using the signature for that of the drawer, or the acceptor, or an indorser; and, in like manner, when a bill is wanting in any material particular, the person in possession of it has a prima facie authority to fill up the omission in any way he thinks fit. (2) Subject to subsection (4), in order that any such instrument when completed may be enforceable against any person who became a party thereto prior to its completion, it must be filled up within a reasonable time and strictly in accordance with the authority given. (3) Reasonable time for the purpose of subsection (2) is a question of fact. (4) If any such instrument after completion is negotiated to a holder in due course it shall be valid and effectual for all purposes in his hands, and he may enforce it as if it had been filled up within a reasonable time and strictly in accordance with the authority given.