I'm offering a lovely Clarke Original whistle in D. It's the nicest Clarke I've played, but I haven't played whistle in quite a while now, so this deserves to go where it can be enjoyed.
The tweaking is as follows: The mouthpiece has been curved so it's more comfortable and thinner than the stock 45 degree angle block. And the windway and blade have been adjusted for best tone and playability (the sides of the block are pinned with tacks). The result is that nice Clarke flutiness without the excess breathiness: a round and focused tone across the range with a sweet and easy high register, plus excellent tuning and intonation.
There's some minor paint chipping in a few spots around the fipple, the diamonds are worn off, and the logo is also mostly worn off, so it's pretty much solid black.
I'll also include 'The Tin Whistle Tune Book' by William E. White, an interesting little collection of late 18th and early 19th century tunes.
$15 including U.S. postage. PM if interested!