Not a Seal, Weights & Measure Verification Mark (Victorian)

Not a Seal, Weights & Measure Verification Mark (Victorian), Image & Found by Sean Flanagan.
Found ?, ?mm.

Crown / VR / 576

From Paul Cannon, "This looks to me to be another weights and measures verification mark. If I am right it is a stamped lead plug from the back of a bronze or iron weight. There is no scale but I am guessing it measures about 1.5cm in diameter. The act for these numbered marks became law in 1879 and so dates from 1879 to 1901, when Victoria died. The number ‘576’ indicates the weight was tested by the authorities in the County of Somerset. For one still in place, for comparison, see Etsy - Iron 1lb Weight - Avery, Birmingham."