The cola add was a late addition to the already ubiquitous image. Strange how this 'urban legend' persists.
For over 130 years, the magazines, Christmas postcards, dolls, costumes worn by parents, etc. had firmly impressed the red-suited Santa Claus in our minds.
He had a green outfit, and a coat decorated with astronomical bodies, until Nast published his cartoons in the 1860's. Later, color postcards printed in Germany (c. 1900) but sold in America showed the red-coated old man with a cane, and a wicker basket on his back, filled with the gifts, but those from 1905 dropped the cane and showed a normal American Santa. American children's magazines from c. 1900 also showed the American Santa, now a typical American, his immigrant forbear completly forgotten.

The poem, "A Visit from St. Nicholas," by Moore, was popular from the 1820's, and may have been written as early as 1807. St. Nick-Santa already had his complement of eight reindeer.

Washington Irving in 1809, A Knickerbocker's History of New York," popularized a jolly St. Nicholas character. St. Nicholas was named the patron Saint of the New York Historical Society (1804).
Accounts from the late 1700's have St. Nicholas visiting the Dutch in New York.
The Sons of St. Nicholas patriotic Society was founded in 1773.

It becomes evident that Pelznickle was a country bumpkin, never of any importance in genteel Dutch-New York and New England society, and had no part in the St. Nicholas (and later incarnation, Santa Claus) of Dutch (and later) American Christmas.

(St. Nicholas was absent from in the Spanish and Mexican Southwest from 1580 until Anglo culture became dominant about 1900; the Kings visited in January. St. Nicholas-Santa Claus was an illegal alien as far as Hispanic culture of the time was concerned.)

Much of this may be found at the St. Nicholas site previously linked; also see www.snopes.com/cokelore/santa.asp.