"Aba" Brown Gelding Mustang

Aba is an adopted horse. We had him for about two years now. He is looking for a new home because we cannot care for him the way we would want due to flooding and lack of a truck/trailer to take him to ride. We would want to give him away for free but we are afraid he ends up in a slaughter house. He has likely arthritis in his left knee/leg. He is fine when there is no pressure on him, and excessive cold without a shelter. He is a kind horse, but not ridden by us. Are you a cowboy? You can tell what he is able to do. We adopted him, took care of him, but want him to be in a better environment.