No. 1 Lever Filler
This pen is from the personal collection of Ariel Zuñiga - a generous contributor on FPN, seminal Montblanc collector’s books, and now this website. Watch out for a series of reviews of truly rare pens thanks to AZ’s generosity!
The No. 1 (Long) Lever Filler is made of hard rubber, and it is a thin pen but not so short with a length of 13.2 cm capped. The not-so-common clip on this pen was made for only a few years between 1927-30. The nib was made from 1924-29. And the lever on this pen was made from 1928-30. Based on the design of these specific parts as per Collectible Stars I, we can narrow down the pen's date of manufacture to 1928-29.
I must say that this pen has exceptionally crisp barrel imprints!
Montblanc made lever fillers for a short period between 1921 to 1929. The lever filling mechanism was already introduced and popularised by W. A. Sheaffer in the US in 1908, but it seems to have taken some time before Montblanc decided to use it too.
It's a pretty simple mechanism, as demonstrated in the picture here.
I wonder why Montblanc didn't use it for longer. But, because they were only produced for a few years, these lever filler pens are considered highly collectable and valuable. A variety of designs have been found imprinted in MB levers, and they serve as hints to the precise period during which a pen was manufactured.
Pic Credit: Colectiblestars.com
For bibliography, see Resources page -->link