The writing instrument described is the Classique Rollerball Solitaire 163 in sterling silver with vermeil thread guilloche and rose-gold trim from the Limited 1924 Edition for the 75-year anniversary. The authenticity can be well checked by comparison with the documented features on relevant collector sites. Further information on this edition can be found on fountainpen.de under the Anniversary Limited Editions. From disreputable auctions in which pictures of real pieces are misused for other types of models, caution is in order.