Statute of limitations for collection of penalties and interest on delinquent personal property taxes. Any interest or penalty on personal property tax levied pursuant to the Revenue Act of 1939 by any taxing district, as defined in that Act, located in a county of less than 400,000 inhabitants, shall not be collected more than 7 years after the date on which the tax was initially levied, notwithstanding any judgment which has been obtained in relation to collection of the tax. For purposes of this Section, “personal property tax” means a tax on personal property imposed by taxing districts pursuant to the Revenue Act of 1939 prior to abolition of authority to impose personal property tax in Illinois.