Very interesting, but I am confused. This is my Suzuki A-25 (with the label “Study 25”). I have two of them, and they play very well. But the tray is metal. The date I see for this on the Suzuki site to which you link is 1968-72, and it does not look to me like your Pianohorn.
Your Pianohorn looks more to me like the first Suzuki Melodion listed on the Suzuki site for 1961-72. That is consistent with the information from the person who gave you the Pianohorn. Here is my guess: That the Tombo Pianohorn was made for Tombo by Suzuki. Several other brands of keyboard harmonicas have been manufactured by Suzuki, including Samick and Kawai. Here is another instrument with the label “Melodihorn” that in fact is a Suzuki A-27. I believe the Samick was made in Korea. The Koreans may have taken the English pronunciation of “Melodion” and written it “melodyhorn” or “melodyhorn” — as we now sometimes see Suzuki “Melodion” or “melodeon” as “Melody On” — I see this as a Google translation of “melodion.” But I do not know either Japanese or Korean.
This is not such a good keyboard harmonica as the Suzuki A-25.
I think your pianohorn is a version of the original Suzuki Super 34. But I could be mistaken!
So the Tokai PC-1 was made in 1961. This is exciting news. All the early Yamaha Pianicas were, of course, made by Tokai Gakki. But I don’t think any of them were like the PC-1, which is more like the design of a Clavietta.