I've collected a number of Waterman ringtops, and most have been variations on the 52 1/2 v model. But I bought one on eBay that's numbered 0682 v: it's a bit thicker than the other model - about the dimensions of a Wahl-Eversharp ringtop. It's got a swell nib, too. Does the collective knowledge base know anything about this model? I'd think it was later than the 52s, but you have to be a necromancer to figure out the numbering system.