Thanks.
I found the picture below by Googling 'Kanto Electric Motor Works cars' in Japanese! Now the problem is deciphering what it says...
It is clearly a model BA, but Google-translating what it says in Japanese beneath it it comes up with "November 24 BA sedan NEC manufacturing automobile 90 units manufactured from November 24 to February 26"!
So is it an NEC Model BA? I didn't know NEC was anything to do with Toyota...
Or is it a Kanto Model BA?!
Must be one or the other, but whatever it's called it was made at the Kanto Electric Motor Works, which was owned by Toyota..