Mine also has the capped drain like the piano 36. Wooden end caps, just a hole for the mouthpiece, no stem. I don’t think the sealant was a sloppy repair-it is also used to seal the reed plates. It appears to have been placed before the reed plates were attached. it is very hard and brittle, not sure how easy it might be to remove.
I am hoping to have some time within the next week to open it back up and effect a repair. I will take some pictures to share. As far as the tone, it is definitely warmer and smoother than the piano 36. Action of keyboard is also a step up, as you might expect. It is a shame Hohner bailed on the professional models.