Cracked. Reads: "I H 1774" Marked three times: "MZ"
Front and back hounds are heavy wooden members of the running gear. Each is configured into a "wishbone" shape whose "prongs" are attached to front or rear axle. Thus, this iron is likely a hound band that encircles and secures the hounds where they are joined to the coupling pole that runs front to back. (These wooden members are part of what we now call the chassis.)
