No. 1B black hard rubber safety fountain pen, SIMPLO imprint, inset white captop star. 133mm. No. 2 Montblanc circle-vent nib, very flexible, great nib. Very fine condition, imprint 65%, barrel partly oxidized.
-Wallrafen, Stefan & Jens Rösler. Collectible Stars I: Montblanc 1908-1947. [Cologne: 2014], pp. 42-43.