My wife and I have a log home that was built circa 1810. During some remodeling we found a brick in what would’ve been an original outside wall between the first and second floor in the stairwell. The brick was set at aproximately 45 degrees in a notched area of the timber with mortar. My question is what was this used for? It seems more like a keystone as the upper floor of the house used to be a boarding house. Could this have been just that for a doorway leading off the stairs to the back