Quoting the certainly well known TLR collector Barry Toogood from his excellent homepage about TLRs: "Obscure in the extreme, Isokawa is credited with just this single model, so far as the standard texts are concerned. The same model appears on a few Japanese collectors' websites, but that's about it. One of those sites seems to say that there was a Model II with self-timer, but no one has any picture of it if so."
Well, here it comes. It is not specifically named as "Model II", but it's a model with self-timer. I found it on yahooauctions this week and I am so happy. It is also fully functioning and the lenses are clean. What a lucky find !!!