Nice find! Blue petal perfume bottle issued from 1979 according to Scotlands Glass website and my Caithness Collectors guide book. I'm sure the base etching goes back earlier than the 80's. I have a number of 70's weights with etched bases.
Don't know when it started or if it has been consistently done as I also have later weights with the names inscribed on to them. Seems to vary a bit!