Antique frame.

Do you know who made this frame? This is the first time I have seen this type of embedded, long, thin, wood piece on the back of a frame. Newcomb Malcom frames are known for having an arrow shaped piece embedded into the corners, however, I don't recall ever seeing this type of thin piece across the center of the miter. Not sure if this is lettering or not in the last photo. I don't have the frame here, but I can get more photographs if needed. Thank you.