That makes sense - I think a Super Azusa service would be the 8+4 car E351 from Shinjuku to Matsumoto.
Then, at Matsumoto, the train splits, and the 8 car portion continues to Minami-Otari (which is on the admin border between JR East and JR West (?)) I think this portion of the journey was referred to as "Azusa" (rather than "Super Azusa").
I wonder what happened to the 4 car portion that was left behind though. Was it used on any services, or did it just sit at Matsumoto waiting for the 8 car portion to return?
I too adore the E351. I have the KATO n-scale model and I have entered to the world of miniature scenery-making just so the model can sit on a diorama that is worthy of it.
I haven't really found much english-language resources on the E351, so anyone can point to me to, or tell me about, interesting stuff about it, I'm all ears.>>1351024
I didn't know that the pendulum tilt was actually damaging the train. Is that why people say the E351 was expensive to maintain?