Forget it - I figured it out myself. For anyone else who finds themselves confused in this situation here is how to change the quantity box to an Add To Cart Button on the All Products listings Page (also works for the New Products page but not the Specials page):
In Zencart Admin go to Configuration and Choose All Listing. Locate "Display Multiple Products Qty Box Status and Set Button Location" and set it to '0'. Next locate "Display Product Buy Now Button" and set this to '1302' or whichever seequence you prefer. The Add To Cart Button will now show instead of the Quantity box.



