(a) Nothing contained in this act shall be construed to empower any school district of the first class to impose, levy and collect the taxes hereby levied upon any personal property of any of the classes hereinbefore enumerated not within the power of the General Assembly under the Constitution of the United States.

(b) If the tax or any portion of the tax imposed upon any of the personal property of any of the classes hereinbefore enumerated under the provisions of this act, or if any exception of any personal property of any of the classes as hereinbefore enumerated from the imposition of the tax under the provisions of this act shall be held by any court of competent jurisdiction to be in violation of the Constitution of the United States or of the Commonwealth of Pennsylvania, the decision shall not affect or impair the right to impose the taxes or the validity of the taxes so imposed upon the personal property of the other classes, as hereinbefore enumerated, or to impose the taxes on the personal property so excepted. It is the intent of the General Assembly that the taxes imposed or excepted, so held to be unconstitutional, were not to be imposed or excepted, as the case may be, but that the taxes imposed upon all other personal property made taxable under this act were to be imposed and that taxes on the personal property excepted were to be imposed thereon.

(c) It is the intent of the General Assembly that the power vested in it to levy taxes shall not be delegated by any of the provisions of this act to any school district of the first class in violation of the provisions of the Constitution of Pennsylvania. If a court of competent jurisdiction shall hold that such power has nevertheless been so unconstitutionally delegated, the rate of the tax herein imposed shall be four (4) mills on each dollar of the value of the personal property made taxable, which rate the General Assembly under such circumstance intends to be imposed.