The Mark Twain was fairly hefty -- think along the lines of the diplomat and great dane. I didn't look at it close enough to see if it had a wooden bottom, but my guess is it does. Imagine a dublin-esque cob -- there ya go. They can't get too creative or fancy and maintain low price/high value.
The Huck Finn is pictured, and the Tom Sawyer looks similar, maybe a bit smaller with a black mouthpiece rather than amber.
Also, the mesh screen is not for smoking "other things". One complaint about corn cob pipes is that if you remove the filter, you end up with bits of tobacco in your mouth. With the mesh screen, you can smoke without a filter and prevent bits of tobacco from moving up the stem.