Where a person accused of an offence under section 103 proves--
         (a) that in the ordinary course of his business he is employed on behalf of other persons to apply trade marks or trade descriptions, or as the case may be, to make dies, blocks, machines, plates, or other instruments for making, or being used in making, trade marks; and
         (b) that in the case which is the subject of the charge he was so employed, and was not interested in the goods or other thing by way of profit or commission dependent on the sale of such goods or providing of services, as the case may be; and
         (c) that, having taken all reasonable precautions against committing the offence charged, he had, at the time of the commission of the alleged offence, no reason to suspect the genuineness of the trade mark or trade description; and
         (d) that, on demand made by or on behalf of the prosecutor, he gave all the information in his power with respect to the persons on whose behalf the trade mark or trade description was applied,
he shall be acquitted.