1941 Double Jewel Blue Diamond Parker 51 set black barrels, first year 1/10 14 K gold filled wavy line caps. This is a very nice late first year set. The pen has all the correct indicators, from a strong imprint at the bottom of the blind cap, to the first year shell profile and all points in between. The pencil has the correct gold washed mechanism and an original eraser and the jewels are (correctly) plastic, rather than the aluminium of the early first year. The nib is a slightly stubbed medium to fine. $650.00 the set.