I have listed two really nice low D’s on ebay,
An excellent condition Kerry Songbird tunable low D, they don’t make these anymore!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300492884643
and a steal on a very sweet sounding O’Brian tunable low D.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300492885302
Also for those who are interested, I have posted a new whistle review for a Reviol low D on The Pipersgrip website:
http://pipersgrip.50webs.com/Reviol.html
Thanks for looking! 
Lowered the starting price on the Kerry songbird.
Wow, where does he hide the tuning slide?
I can’t see the seam.
and a steal on a very sweet sounding O’Brian tunable low D.
That typo could lure people into thinking the whistle is a Cillian O Briain one.
Until they see the picture. Or read the
ebay page with the correct spelling. I
think they’ll be alright.
No seam! The head moves inside the tube, I believe. Here’s a pic of the head from David’s site.
That’s so obvious, I’m surprised I haven’t seen it before. Spiffy.