The letter W and partial mark above it have the correct orientation to be the "WR below a crown" marking on British-made padlocks produced during the reign of Britain's King William IV, 1830-37. (See the orientation of the markings in the photo attached below.) The crown with WR marking stands for "William, Rex" which is Latin for "William, [the] King." Also, your keyhole-cover's shape is correct for that era. So, although much of the marking is indistinct, that's my "educated guess" about the marking on your padlock keyhole-cover, and its time-period.