The premises to be used by a manufacturer of tobacco products as his factory may consist of more than one building, or portions of buildings, which need not be contiguous but must be located in the same city, town, or village: Except that, where the appropriate TTB officerdetermines that a building or portion of a building which is not within the city, town, or village, is so conveniently and closely situated to the general factory premises as to present no jeopardy to the revenue and as to offer no hindrance to the administration of this part, he may authorize the inclusion of such building or portion of building as part of the factory. The buildings or portions of buildings shall be described in the application for permit and the bond by number, street, and city, town, or village, and State. If any of the following conditions exist a diagram shall also be furnished, in duplicate, showing the information indicated:
(a) Where the factory is in more than one building, and each building is not identifiable by a separate street address - identify each building by a letter, number, or similar designation;
(b) Where the factory consists of a portion of a building or where portions of buildings are part of the factory - show the particular floor or floors, or room or rooms, comprising the factory;
(c) Where there is an adjoining retail store operated by the manufacturer tobacco products including any doors or other openings between the premises.