Dick, Thanks for the excellent response. I first noticed my Wood dust allergy when someone used my wood lathe to cut and sand some cherry wood. That was more than twelve years ago. Since then I have discovered that more and more woods bother me when I cut them with electric tools. After the first incident I gave up most wood working other than very short projects around the house. I also have a known allergy to a couple of foods and one size of dust mites. None of these are immediately life threatening. However, as I am 81 years old I take a lot of care. To test if it was the wood or perhaps mold (I am sensitive to molds too) Bill Lazar suggested that I fill the windway with Duponol and hold for a couple of minutes then wash it out. I did that and then washed it out and let dry for a couple of days. To test I held the mouth piece in but not touching my mouth and breathed through my mouth. Symptoms returned. By the way, my Denner is in pearwood with, of course, a cedar block. I read somewhere that “all wood recorders” have cedar blocks. While I doubt that there must be a very good reason for the extended use of cedar which unfortunately out gases for years. Bill Lazar also suggested I wrap the mouth piece in Saran Wrap. However, my test proved it was an inhaled allergen. I do like your suggestion about another block but allergists have never been successful at helping me personally with problems such as my dust allergy. I am also rare in that I have problems with most synthetic drugs. I began having trouble with some of the medicines that they prescribed to inhibit my dust allergy. Also because I develop more and more allergies as I grow older I choose not to go on with a wood instrument. Yes they sound better but I do like the sound of plastic recorders though they are not as consistent throughout their range as my Denner is. I will live with that and be content.
One last point: I will continue to play recorders as long as I can because they are the only completely free blowing wind instrument there is. All others restrict the air flow in one way or another. The free blowing aspect makes recorders the best wind instrument to help you turn over lots of air. The more air you can turn over in a gentle way for more than just a few minutes at a time is an excellent health serving activity. Both my wife and I started this last Xmas and we have improved steadily. Bill Young