The said bonds signed, countersigned, endorsed and sealed as provided in this act N.M. Stat. Ann. § 6-12-6 to 6-12-14, and coupons thereto attached, when sold, shall constitute a valid and binding obligation upon the state of New Mexico, although the sale thereof be made at a date or dates after the persons so signing, countersigning and endorsing same shall have ceased to be the incumbents of their respective offices.