The L129 is very rare and difficult to value because of missing comparison sales; estimates in the four- to low five-figure range are only vague benchmarks, since serious collector price lists for historical Montblancs do not exist. The correct L129 carries three cap rings: a wide, gilded middle ring as well as two narrow silver rings above and below. The narrow rings were not gilded. A known earlier auction with closing price 5,520 DM (not euros) was reversed; the example in the Montblanc museum is regarded as a reference. eBay as a sales platform is disputed, since rare pieces do not necessarily achieve their actual collector value there.