(a) The bonds shall be in such form and denomination, have such dates and maturities not exceeding forty (40) years from their date, bear interest payable at such times and rates, be payable at such places within or without the state, and contain such provisions as to registration of ownership if the commission thinks registration is desirable, all as the State Highway Commission shall determine.
(b) The bonds shall be signed with the facsimile or lithographed signature of the Chair of the State Highway Commission and with the manual signature of the secretary of the commission.
(c) The coupons attached thereto shall be signed with the facsimile or lithographed signature of the chair of the commission.
(d) The delivery of the bonds so executed shall be valid, notwithstanding any change in the officers occurring after their execution.