Since this is such a generic bottle, I believe your best bet is to do some deep digging on eBay in hopes of turning up a match. I can help you a bit by saying I have associated the D-126 number with both the Wolfschmidt Vodka brand and the Calvert whiskey brand.
You might try searching eBay on these search phrases:
Ball decanterCalvert decanter or Calvert bottle or clear Calvert bottleWolfschmidt vodka decanter, etc.It's a long shot but try D-126 decanter or D-126 bottle. Putting "D-126" in quotes may and searching the body of listings may also help.
There is no easy way here - persistence pays off.