It shall be competent for any such police retirement fund to take by gift, grant, devise or bequest, any money or property, real, personal or mixed, in trust for the benefit of such fund, and the care, management, investment and disposal of such trust funds or property shall be vested in the officer or officers of such city having the management of such police pension fund, and the said trust funds shall be governed thereby, subject to such directions not inconsistent therewith as the donors of such funds and property may prescribe.
53 P.S. § 762