I'm splitting the Bullhead post into 2 parts, this one will deal only with the black variety which Japanese collectors have called "Kuro Uma", which translates to "Black Horse", while in the West it is called a "Black Bullhead". Another name for this style is "Mickey Mouse" - the pushers are Mickey's ears. Two different specimens of mine are shown in the following pictures; 1st has had a case reconditioning [so NO original factory texture] while the 2nd seems to have lots of original texture:
The dial pictured above is the ONLY style that is "factory original". There are aftermarket dials for sale now with "Speedtimer" markings and various other color schemes. Some are quite well made, but if you want a "fully original" Kuro Uma make sure you get one that looks exactly like those pictured above! Only the "Cha Uma" [Brown Horse or Brown Bullhead] came in both export ["Chronograph Automatic"] and JDM ["Speedtimer" or "5 SPORTS Speedtimer" depending on date of production] dial varieties.
From the rear, showing the correct original bracelet:
The Patron Saint of Seiko Collectors