War Admiral, (foaled 1937) chain through mouth https://thevaulthorseracing.files.wo…portraithi.jpg
Seattle Slew, chain over nose (scroll down for pic) https://www.horseracingnation.com/horse/Seattle_Slew#
Mr. Prospector in 1981, chain through mouth https://en.wikipedia.org/wiki/Mr._Pr…Prospector.jpg
Nashua in 1981 https://en.wikipedia.org/wiki/Nashua…lem_Brooks.jpg
While looking for these photos I saw a couple of other stallions, including Man o’ War, wearing bridle headstalls with bits, and the lead shank chain looped through the bit rings.
Hope these help answer your question, Maythehorsebewithme.
(I guess I was keeping track mentally, because I remembered seeing pix, and I found some online! )
Looking for these online, I looked for stallions who had reputations for being “difficult” (to say the least) and was interested that they did not have chains over their noses or through their mouths. Whirlaway (f 1938), Fair Play (1905), and his sire Hastings.