The accordion treble mechanics are very different compared to accordion factory’s later models. The treble structure is very similar to Giulietti’s stepped keyboard accordions made in New York in the 1920s, and at the same time it is nowhere near the Italian Cooperativa accordions from this era: the two inner key rows attaches to the main arms with lifting levers (brass). The key rows number 4 and 5 are wooden. The outer key arms are also wooden. The structure proves that the Finnish accordion industry used American accordions as examples of manufacturing, as Italian accordions where used, too.
The sound boards are plywood and all the reedblocks are made of spruce.