(b)The Collector may grant a licence for vend of stamps to any person or class of persons deemed by the Collector to be fit and proper persons for the sale of such stamps provided, that the Collector may at any time at the request of such person, approve the name of the agent of such person who may carry on the vend of stamps when such person is sick or unable to conduct his business due to unavoidable circumstances. The name so approved shall be entered in the licence. Such an agent shall, during the period, he carries on the vend of stamps, be deemed to be a person licensed to sell stamps and be liable as such.]