Could be,judging from your description it sounds like a Willard. Definitely Sparta made I'd say.Probably made as a basket pipe.I just picked up a pipe with the labellin "tinderbox" on thye side from ebay. It has a yellow dot on the side , a ball type stinger , aluminum thread on shank that can be turned to adjust the bit position.
it smokes and looks great , and I'm wondering if its a willard.
Basket pipes,from what I gather,were not a large percentage of their total production. Cruising Ebay one can see examples if you know what you are looking for. Sparta-Grabow shapes are not hard to recognize if you are familiar with the MANY different shapes they made. Usually those pipes will be unstamped or stamped only "Imported Briar" and may or may not have a spade on the stem. Rarely,will they have the name of the store or company they were made for. They also made promotional pipes. Half & Half,SWR, Mobil Oil and others. These will be stamped.@ ejames sounds like a lot of sparta were "basket pipes" by design ... If I could figure out how to post a pic I'd throw it up.
cheers