Interesting. The Black Shadow came out in 98. I only have catalogs through 99 but in both of those years the Black Shadow was a push feed. In 98 and 99, it did have the same stock you pointed out in the GB add (a push feed) which appears to be the same as the Synthetic Matte; no W imprint. In 98, Winchester describes it as "Durable, moisture-resistant composite stock." Guess i need to keep adding to my catalogs.
Regardless, it's a great shooter!