Jorgen, there are a couple of models missing on the yamaha list. and a lot of them are no arranger keyboards. Basicly it all started with auto accomp. way back around 1970. I think Solina was one of the first brands which came with a homecabinet organ with autoacc., soon followed by the italian brands and yamaha. Yamaha also had an early small keyboard just called PRS or PSR which had an autoacc. around 1972.
Did not see it in the list of Yamaha. There was also a strange cabinet called Optigan, which worked with some kind of tapes for the autoacc. also from the early seventies.

Just my two cents..