Administrators, executors, custodians, conservators, guardians, trustees, and other fiduciaries, insurance companies, business and manufacturing companies, banks, trust companies, credit unions and other types of similar financial organizations, charitable, educational, and eleemosynary funds and organizations, and all agencies, localities, and other political subdivisions and governmental units of the Commonwealth are specifically authorized to invest funds held by them, without any order of any court, in accounts of savings institutions authorized to do business in the Commonwealth. Such investments shall be deemed and held to be legal investments for such funds. The provisions of this section are supplemental to any and all other laws relating to and declaring what shall be legal investments for the persons referred to in this section.