I think you're referring to outside wooden stems (i.e., outside the canvas) bent around the ends of the canoe and mating with the keel. If so, you can tell how your Old Town was built in three ways. First, outside stems would have been noted on the build record if the canoe had them. Second, if the ends haven't been too badly altered over time, especially if this if the canoe's first restoration, you should see on the face of the canoe's inner stem only small holes from canvas tacks and somewhat larger holes (about 1/8" or less diameter) from stemband screws if it lacked outside stems. If it had outside stems, you'd see another set of even larger screw holes where the outside stem was screwed on. Third, on a canoe with outside stems, the face of the inside stem and planking is considerably wider (about 5/8" or a little more?) than on a canoe without outside stems (about 3/8" wide). That is, in the latter case, the stem/planking face needs to be wide enough to accept the stemband only; in the former case, the stem/planking face needs to be wide enough to accept the larger backside of the outer stem.
If your canoe didn't have outside stems, the keel would be tapered down in width (t 3/8") and height (to a feather edge) well after the point where it lands on the inside stem.
Michael