Thanks to Adam, a friend of mine that collected Michter's decanters, I now have two Sour Mash decanter prototypes. Shown in the photo below are what appears to be (From right to left) the original mock-up, a revision without full paint, and the commercially released decanter. The Sour Mash decanter was released as only 500 decanters in 1985 to commemorate the distillery dog of the same name. Yes, Michter's had a dog that lived at the distillery!
Let's take a look at the three decanters individually. First, let's look at the original prototype. Note the larger ears, more texture for the fur, differently shaped nose and mouth, and small barrel. The paint detail is excellent as well.
Next is what appears to be a production body and head but with no dark fur highlights. Note how many of the details of the prototype have been smoothed over and the barrels has been greatly enlarged.
Lastly comes the version the public got. Less detail, large barrel, dark fur highlights, and a Michter's Sour Mash sticker glued on the barrel and a clear Michter's whiskey sticker on his butt (See above photo showing rears of all 3 decanters for detail of this sticker).
And for comparison to the real deal, I present Sour Mash the distillery dog!
If you'd like to order a Sour Mash, you're 38 years too late. However, here's the original advertisement announcing the decanter's arrival......