Oh there is plenty of horse-drawn equipment around here, young gun. It's just that it's hidden in the willows and cedars. I've got an old JD horse drawn rake that is for sale if you want it. Just start asking around. Cultivators and plows could be a bit more rare. There has been a fair number of old horse drawn mowers at auctions in the past, so they are out there. Dump rakes seem plentiful. I can give you a heads up on one of those.
Because no one pays anything for steel around here and no one wants to haul old scrap equipment (highway regulations), there is a fair bit of stuff laying around. I know a neighbor that hauled a bunch of old horse equipment to the dump last summer to become a crumpled mess. Actually, I probably could set you up with a old disc for horses a well. Of course everything you buy is going to need work, so best try and find yourself 2 of everything.
Burnt, any of these ring a bell:
Olcott, Hematite, Sapawe, Blalock, Kawene.