(1) In addition to these penalties or enforcement proceedings provided for in Chapter 19-500 of this Title this Chapter may also be enforced in accordance with other penalties provided for in the Act known as the First Class City Business Tax Reform Act.

(2) If any tax authorized or imposed under this Chapter was not paid when due or is not paid when it becomes due, there shall be added to the amount of the unpaid tax and collected therewith interest at the interest rate imposed by the Commonwealth on unpaid taxes pursuant to Article VIII, Section 806 of The Fiscal Code (72 P.S. Section 806). The interest imposed pursuant to this Section shall be in lieu of interest charged pursuant to § 19-509, but all other provisions of § 19-509 shall apply to this Chapter.^[367]