I asked this same question the first time this canoe was offered on eBay-- those rush seats are deceiving... we even have a Shell Lake (well, parts thereof) and have that deck and carry thwart combo.
The second time this seller listed the boat, I thought I'd let him know what it might be, but received a snippy response doubting anyone's ability to determine a canoe's maker based merely on a picture. Heck, some canoes can be diagnosed, based on a picture of the stem alone!
Kathy