The only markings found were Ardsley and Y&T, I assume for Yale and Towne.
This product is a lot of 18 antique/vintage Victorian back plates, featuring a gold color and made of bronze, brass, cast iron, and nickel. These back plates are original antique pieces, reclaimed from the past. The maker is unknown, adding to their historical charm and mystery. Perfect for adding a touch of Victorian elegance to any door or piece of furniture, these back plates are a unique and timeless addition to any collection.