Thanks Whaler for you input. This flute has an odd story to it. With mortgage, kids etc I couldn't possibly afford a Haynes. For many years I have used an Artley Artist, which I actually like, but it has its foibles. I was passing a yard sale and there was a table with a sign, 2 old flutes $60. One was a really nasty looking old Armstrong, the other the Haynes Commercial in question with original case, case cover, tenon covers and rod 23,000 serial number. Suffice it to say I bought it. It needed cleaning, oiling, full repad but now that it has been done over it has a lovely sound. To resolve the story, I took Bruce and saxoclese's advice - tapped the crown a little, used gloves to twist it a touch, then tapped the crown from the inside gently 'up'. It was loosened and raised just enough to get enough purchase to loosen unscrew it. There was quite a bit of green residue and white salty looking matter on the crown thread and the inside on the head joint. I have cleaned and oiled the thread and cleaned the inside of the head joint and now it is functional once more. Thanks a lot everyone!