Earlier Valentines had a numbering system based on price - so you can get a 106, which cost 10/6, a 210 (a guinea or 21/-) 250 (25/-) etc. but the later pens had a numbering system based on size 01 (also occasionally N01) 02, 03 and 04. They are most commonly seen in the red, green and brown candystripe colours but were also available in in many, if not all, of the lovely English Duofold colours that David Shepherd shows on pages 262 and 263 of his Duofold book. They came as both button and lever fillers.
The 06 size Paul refers to may be the pen on the right of the picture which has a Valentine nib and clip, but only s "Made in England" imprint and no number on the end. Left to right, Valentines 01, 02, 03, 04, Parker Victory, Parker Duofold Senior (I think) and the "06"
Edited by Wardok, 08 March 2014 - 12:59 AM.