I've seen some in HO over the years, but don't recall any details on who made it. I may have seen it while in japan, and if it was there, it was incredibly expensive!
I bought some low-end "models" (no power, rough detail, very toy-like) of the Shinkansen and others in N scale while I was there in the 90s.
Someone made a fantasy version of a shinkansen Amtrak in HO, I think I've got a version of it somewhere upstairs. It's very crude iirc.