Excellent discussion and very nice job on the video. I have two P-32Ds and had problems with one key (different keys) on each of them. Others have reported the same problem with the P-37D. It’s easy enough to take the P-32D apart, but I have had success in addressing the problem by alternately blowing and sucking the melodica with the offending key depressed. I suppose this may change the gap, though the subjective feeling is that I’m loosening the key up. I do this now with other melodicas when a key seems to have gotten out of tune, and I find that I can work the reed a little bit to change the intonation. I agree with your assessment of the P-32D, Rodrigo.