All nonconforming uses and structures legally existing at the time of the adoption of this chapter and all uses and structures which become nonconforming by reason of amendment thereof may be continued.

Nothing in this article shall be deemed to prevent keeping in good repair a building in which a nonconforming use is conducted.

A nonconforming use may be changed to another nonconforming use of the same or a more restricted nature.

If any nonconforming use is abandoned for a continuous period of two years or more, or is changed to or replaced by a conforming use, or is moved for any distance for any reason, the land and building theretofore devoted to such nonconforming use shall thereupon be subject to all the regulations as to use for the district in which such land and building are located as if such nonconforming use had never existed.