On the one hand I have recommended that guy many times when the only parts that exist will have to be sourced from Japan. He's the go-to specialist for that. Expect this to be expensive, he spends a lot of time on research.
On the other hand I've only bought from him once. He's a legitimate Yanmar-USA parts dealer so when I bought the first Yanmar I bought a replacement genuine Yanmar clutch safety switch from him. The rubber accordion shield disintegrated the first week. It must have been ~30 year old stock. "Sorry, no returns on electrical items".