How wide is the slot? I can see this being a home made saw set for a large diameter head saw before the days of carbide inserts. These old saws,if I remember correctly, had about a 3/8" to 1/2" kerf, maybe even more depending on how the teeth were set. No idea what the curved down ends were for. The arms may not be long enough to get the amount of pressure needed to bend each tooth with a reasonable amount of accuracy.