There is a Overton Low D for sale on Ebay.http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2545977920&category=308&rd=1
Probably the one mentioned in this thread:
http://chiffboard.mati.ca/viewtopic.php?t=12905
All the Best, Tom
Nope! Mine is the one with the starting bid of $135 – not (!) $225 – and is the one without the photo (no digital camera, I’m afraid). Also, mine is a Goldie, and the other one appears to be a Bernard Overton model. The seller of this one also seems to be unaware that one can get Bernard’s Overton whistles in the States (Hobgoblin Music carries them, I think, and they can be ordered from overseas just as Colin’s whistles can).
Seeing that the same fellow recently sold a Bernard-model for $250 on E-Bay, though, I’m starting to wonder if I shouldn’t have placed a much higher reserve price on mine. . .
Doh- Sorry Herbivore- I couldn’t get the link to work, and when I just kind of searched Ebay, yours is the one that popped up. 
All the Best, Tom