Where uncertainty exists with respect to the boundaries of any of the zoning districts as shown on the Master Zoning Map, the following rules shall apply:
(a) Where district boundaries are indicated as approximately following the center lines of streets or highways, street lines or highway right-of-way lines, such center lines, street lines or highway right-of-way lines shall be construed to be such boundaries;
(b) Where district boundaries are so indicated that they approximately follow the lot lines such lot lines shall be construed to be such boundaries;
(c) Where district boundaries are so indicated that they are approximately parallel to the center lines or right-of-way lines of highways, such district boundaries shall be construed as being parallel thereto and at such distance therefrom as indicated on the Master Zoning Map. If no distance is given, such dimensions shall be determined by the use of the scale shown on the Master Zoning Map; and
(d) Where the boundary of a district follows a railroad line, such boundary shall be deemed to be located in the middle of the main tracks of such railroad line.