Raseyn, of the famous brothers "Raffles and Raseyn" was trained five-gaited. Arieana Arabians - Heritage Notebook: R (*Raseyn, Raseyna)
Where it says:
Raseyn was the first stallion by Skowronek to come to the United States. He was a regular feature in the Kellogg Sunday Show, being trained first as a jumper, then for five-gaits at which he was fairly fast at the rack, though not quite with the speed and form of a Saddlebred.
My 27 yo Arab has two crosses to both brothers. While he exhibits a lot of Raseyn's gentle personality, he never has been inclined to gait. But I rescued him, 20 years ago, with a serious vertebra injury, so who knows.