I recently purchased a Hohner Professional 36 from one of our fellow Melodicaworld members so I could have extra reeds for my other Pro-36 and Solist melodicas. Ittook a picture of the gasket that I removed and there was a date of March 1962. This Melodica does not have the standard moisture plug but a button just like my Solist. Now the Professional 36 has the logo of the Hohner man playing an accordion but my Solist only has the words made in Germany and the only logo is that of the word Hohner in the same font as all my other Hohner Melodicas.
I also wanted to purchase this melodica so I can get into it to see how it works. For my first experiment I wanted to create a air chamber that I could replace or repiar easier. The current design is that the gasket seals lay on the wooden frame. I removed all the gaskets and cleaned the removed the adhiesive and purchased some window and door seal from the hardware store $6 bucks and created a seal chamber on the metal cover and did not attaché them to the wooden body of the frame, Bam it worked and sealed better than the thin material that was on the melodica. Air tight seal now. I did notice that there is a small leak coming from (2) key pads So that repair is next.
Please see pictures attached.
Monsters of Melodica