I have the YR60 (60in deck) 1980 model, bought it in 1990 and still going today. (actually just change the axle seals #1902-012 this week first time since i owned it)
https://irp-cdn.multiscreensite.com/2f655c0b/files/uploaded/Yazoo-YR-36YR-42YR-48YR-60YR-76TRAILERYT-10HD%281%29.pdf...