The two nib sizes -
Leaflets c1937 – note the three original Magna colours/trim – Golden Brown Visible, Silver Visible and Black Engraved.
The smaller ‘Standard’ 6233/4/5/6 series includes a Blue Visible and a Green Visible. The Silver Visible and the Green Visible are obviously different colours.
The Onoto instructions are more informative than most. They show what is inside the pen and clearly explain the ink cut-
The dismantled post war 1876 – note the finned feed, single piece clip with wide washer, hard rubber rod and ‘necked’ No 7 single colour nib.