The Conway Pen: (Short & long versions. Small or large number alone on third line, either No. 759 or No 759 = early) or Conway Stewart 759 (Short & long versions. Number on first line = later). All with diamond clip, 1 band, j bar, nib CS 2. Some with diamond shield on lever, some with round shield. Dimensions - length: 12.6 -13 cm; barrel+section: 10.1 - 10.4cm; cap: 5.8cm. (Matching pencil Nippy or Duro-point).

Hi Paul, if you're after vintage Conway Stewart info then it's always worth visiting the late Jonathan Donahaye's site. This is what he says about your pen.