There is this brief entry at Antique Sounds Workshop, apparently from 2011:
“The Adler-Heinrich workshop was forced by economic circumstances to close its doors in late November of 2006. We acquired as many instruments as possible before the shutdown and have gradually sold them off during the past five years. Unfortunately, our inventory is now completely exhausted and there are no more of these instruments to be had.”
Given that ASW seems rather picky about the instruments they sell, I would take this as an endorsement.
I am barely a recorder novice, but I do own a (maple, I think) Adler alto, model unknown, which I seem to have ruined by leaving it unattended through several Maine winters. It had a soft and pleasing sound while it lived.
I’m thinking that by “Maine Winter” you mean super-dry indoor heating, but not leaving the instrument in direct sunlight. My experience is that Recorders are extremely responsive to everything.
If your Recorder is bone dry, you should break it in just like a new instrument. Play it for no more than ten minutes a day for a week, and then not for more than half an hour say two weeks. Sudden wetting can make a dry Recorder crack. It’s then time to oil the instrument taking on the re-oil schedule of the type of oil you chose – almond or linseed. Read up on the flammability of the oils.
Despite your home being a dry environment, don’t put it away in a sealed case for at least a day or two after playing. A wet instrument in a sealed case will grow mold and fungus – evil stuff. I leave all my (many) recorders out in a room with good ventilation, meaning circulating air.
I don’t usually buy maple Recorders, but there’s a little maple Moeck Soprano that came bundled in an eBay purchase I made and that is next to me as I write this. I ignored it for about a year and then started playing it now and then. It’s defied all my expectations. It has a sweet, sweet solo voice that’s absolutely even and “flute like” (not reedy) for its full two octaves +2. Not one ‘buzzer.’ I’ve become very fond of it. Who’d a guessed.
All I can say is, may your instrument come alive and give you wonderful music.
— k —