Purpose. It is the purpose of this article to recognize that if a lot legally existed, was used for a then-lawful purpose or in a then lawful manner, and/or contained a legally existing structure, prior to the enactment of a zoning provision in this chapter, or in any amendment, reenactment or replacement thereof, which no longer permitted and rendered the same nonconforming, such lot, use and/or structure is generally held to have a vested right to continue such nonconformity, subject to the right of the Township to regulate any change, alteration, reconstruction, reestablishment, expansion, destruction and abandonment of such nonconformity in accordance with the Pennsylvania Municipalities Planning Code and general case law.