Where the indebtedness to be funded or refunded is secured in whole or in part by a lien, mortgage, or deed of trust upon any property belonging to the municipality or by a pledge, assignment, or appropriation of certain revenues or resources of the municipality, such municipality may make a new lien, mortgage, or deed of trust upon such property or a new pledge, assignment, or appropriation of such revenues or resources to secure the payment of the principal and interest of such funding or refunding bonds, subject, however, to any valid prior liens, mortgages, deeds of trust, pledges, assignments and appropriations.

Municipalities are further authorized to pledge, assign and appropriate to the payment of the principal and interest of funding and refunding bonds issued after February 15, 1933, the collections or proceeds of any or all uncollected special assessments and any or all moneys to be derived from the sale or transfer of tax sale certificates and deeds and from the operation, sale, transfer, or lease of any real estate if such certificates, deeds or real estate shall have been acquired prior to the issuance of such funding and refunding bonds in connection with the enforcement of liens for taxes or special assessments, subject, however, to any other outstanding pledge of such special assessments, certificates, deeds, or money theretofore made.