The records of the Secretary of the Commonwealth and all returns, nomination petitions, certificates and papers, other petitions, accounts, contracts, reports and other documents and records in his custody shall be open to public inspection, and may be inspected and copied by any qualified elector of the State during ordinary business hours at any time when they are not necessarily being used by the Secretary of the Commonwealth, or his deputy or employes having duties to perform in reference thereto: Provided, however, That such public inspection thereof shall only be in the presence of the Secretary of the Commonwealth, or his deputy or one of his authorized employes, and shall be subject to proper regulation for safekeeping of the records and documents, and subject to the further provisions of this act.