The bonds issued pursuant to this chapter shall be legal and authorized investments for banks, savings institutions, trust companies, building and loan associations, insurance companies, fiduciaries, trustees, guardians and for all public funds of the Commonwealth or other political subdivisions of the Commonwealth. Such bonds shall be eligible to secure the deposit of public funds of the Commonwealth and public funds of counties, cities, towns, school districts or other political subdivisions of the Commonwealth. In addition, the bonds shall be lawful and sufficient security for deposits to the extent of their value when accompanied by all unmatured coupons.