Fed up with younger girls and their superficiality, the "old pony" he searches for is a mature woman. In the first verse, the cowboy has settled down "with the touch of her hand" In the second verse, he laments the inexperience of youth and rejoices that a woman "great god knows how its done." In the third, he rejects a sleek, faster life in favor of a more meaningful existence. Also, I think the "saddle and straight shootin' gun" is a metaphor for working equipment and the energy to enjoy the ride...
