Each stamping agent may set aside such portion of the stamping agent’s stock of cigarettes as is not intended to be sold or given away in this state and it will not be necessary to affix the stamps or tax meter impressions thereon required under section 77-2606, except that if such stock is not disposed of and out of the possession of the stamping agent within thirty days of the date of receipt thereof, the cigarettes, packages, or pieces shall immediately be stamped as required by sections 77-2601 to 77-2615. Each stamping agent shall immediately mark in ink on each unopened box, carton, or other container of such cigarettes, received and the date of receipt and shall affix the stamping agent’s signature thereto. Within forty-eight hours after such box, carton, or other container is opened, the stamping agent shall immediately affix such stamps or tax impressions to each package and cancel the stamps affixed thereto.