This is one of the rarer 1970s-80s Suzuki Melodions and was in production from 1972 to 1987. It is also unusual in that it is (so far as I have been able to determine) Suzuki’s only 26 key model, and in that its key range is roughly midway among 25-27 key Suzuki models between alto and soprano, with exactly the same key configuration, however, as the original (small key) Hohner Piano 26 (soprano!).
As with some other Suzukis from the period, when the case is open, the School 26 can be played with a tube in the case, as shown in this photo in the accompanying brochure:
A more muted sound is produced in-the-case.
This has, in my opinion, what is by far Suzuki’s worst spit valve mechanism. Air and moisture are vented out of the same hole into which the button is pushed and hardly anything comes out — same mechanism as on its contemporary Soprano 27. (I’m speaking now of the ones I own: different production runs of the same model sometimes have different venting mechanisms.)
The main gasket on this particular item looks brand new, and the reeds are in excellent condition. Except for some discoloration at the mouthpiece end, there’s very little evidence of this Melodion having been played much. However, there is pretty clear evidence of post-factory tuning, and the tuning (measured at A=441) is very good, almost all keys within +/- three cents.
Here is this A-26 in comparison with other contemporary small-body Melodions.
From top to bottom, (1) 1970s Suzuki Soprano 25, (2) this A-26, (3) Suzuki Study 25 (A-25), and (4) (refinished) Samick version of Suzuki A-27. The A-26 is most similar to the A-27. All four models have the same type of sound, but in my opinion the A-25 is the best of these models, in terms of construction, key action, and sound — following in the footsteps of the earlier (1960s) A-25.
However, a fan of 25-27 key melodicas is likely to have preferences with regard to range, both in relation to the kind of music you’re playing and in relation to particular tunes and the key you want to play in. I found in switching between the A-25 and the A-26 that one or the other works much better than the other for some tunes.