Way out of my budget zone but this may interest some of you with the cash. http://www.ebay.co.uk/itm/Very-Very-Rare-Pat-ORiordan-Irish-Low-Whistle-D-/171903994188?.
Way out of my range too. Pretty, though.
Not enough supporting information as in what the whistle is made from, metal, wood, whatever. Could’ve provided the serial number if there is one in the traditional markings. And the image is low whistle quality here for a whistle with only twenty hours use from new. The bag shows more wear than that. Hmm… eThingy!
Too expensive for mere mortals I am afraid. 
But you just missed out on a D/Eb set at a decent price.
http://www.ebay.com/itm/281776877210
Yes, eThingy. But it is one of Pat’s. You can kind of see his signature on the head. If you’ve played one that’s enough to know. They are made of tough stuff. Really.
Feadoggie
Yes, I saw that Feadoggie but it’s not a decent price by the time you add shipping and 20% import duty plus processing fees.
I hear you, Mike. Too rich for my blood as well, even without the import fees.
It’s not the usual week when two O’Riordan low D’s show up on eBay.
Feadoggie
I realize this one is gone and I’m not really looking. I know P.O. made great whistles.
Wouldn’t the extra joints allow more opportunity for leakage with normal wear & tear?
And, just curious if this whistle set is possibly the same one?
Opportunity? Perhaps. But in practice a well made joint will work and seal well for ages. Look at all of the timber flutes with the tuning slide, separate hand sections and a long foot joint floating around for more than 100 years that still play well. Cork or thread on joints is meant to be maintained/replaced. Metal to metal joints may wear a little over time but they are still easily sealed by waxy joint compounds or PFTE tape at the worst. A little delrin lasts a long time if that is employed.
Whistles do tend to be less complex in the format of their construction however many makers realize that the added joints provide greater usability. Burke, as just one example, uses a lot of parts and joints on his whistles too, particularly on the low D types. I have examples which while merely in their adolescent years work just as they did the day I received them. The ability to rotate that lowest hole really makes a big difference in fitting many hands. And if you look around you will see that Pat O’Riordan used a few different joint methods over time. So I would think he was aware and willing to improve any design issues that may have come up in his whistles. That rotating bottom hole tactic used by O’Riordan (and then Burke) is not lost on some of us DIY makers.
I’d not be concerned much with the joints on one of Mr. O’Riordan’s whistles. His whistles play well and sound lovely. If you really want one (or need one) you probably would take one even if it had a wart on the nose, so to speak, and likely would not think about the type or number of joints.
I’d venture to guess that a lot of folks came to want to play the whistle based on the sound of a particular bunch of Pat O’Riordan’s whistles.
Hard to say. Nicer price though. I do not see photos on that link, can’t compare the whistles. They are offered by different sellers in different states. There were a fair lot of Pat’s whistles being played in the 90’s and early 2000’s. Could be another set. Could be a re-sale. But I would postulate many of these types of vintage whistles get bought by a certain re-seller anyway to keep up the level of the second-hand market - if that’s what you are thinking.
Feadoggie
The one in the current ad says 2002, and that one is 1999. To my knowledge, they were all aluminum when lower than his ‘Concert C/D’ which was often sold as a set. The wooden bflat that I have is the lowest wooden one of Pat’s that I have run across.
Thanks Feadoggie and rhulsey for the info. Being that I’m not a frequent flyer on eThingy I only recently discovered that old transactions discard the images, oh well, that is why I was saving the transactions in the first place for the pics. Time to clean out file. 
For what it’s worth, my O’Riordan low D is from 2001 or 2002, appears similar to this one, has seen extremely heavy use over the years, and doesn’t leak.
BTW, as far as I know Pat only ever made aluminum low Ds. (Of course, his workshop was absolutely loaded with experimental whistles, so it’s certainly conceivable he has a wooden low D out there somewhere.)
And, just curious if this whistle set is possibly the same one?
Definitely not, the D/Eb set there were high whistles.