Mother's Oats cerial

The coupon was found by my husband inside a wall of a house he was tearing down a few years ago. It's a profit sharing coupon for 1/2 cents off of a package of Mother's Oats cerial. I researched Mother's Oats and what I found interesting was Mother's Oats was bought out by Quaker Oats in 1911, but this coupon is distinctly for Mother's Oats brand in 1913 and refers nothing to Quaker Oats. We'd like to know what this piece would value. I can email a photo.

Fair