What is described is a four-colour pencil, probably from the 1930s, in which different leads can be advanced alternatively via four sliders and the lead reserve is stored in the rear container under the screw-off cap. Collectors point to illustrations of similar models in the Rössler book on Montblanc, in which, however, no clear model numbers are documented for these early four-colour pencils, since Montblanc did not consistently work with model numbers at the time. An angular variant is shown on fountainpen.de under old-30er-4-colour-pencil; round versions with a circumferential clip ring are rarer but contemporaneously documented. An exact value statement is not possible without photo and condition assessment; collectors recommend posting good detail pictures on the forum and consulting the relevant collector literature (Rössler, Tischler).