We have previously posted about Waterman’s Coin-Filler fountain pens. In 1908, Waterman released the self-filling pen, but by 1913, the sleeve-filler was improved and The Coin-Filler was launched under a special licence from Conklin. Each coin had a unique key number, making them something fun and interesting to collect today – if you can find one. A great vintage pen, indeed!
Waterman: Past and Present
Max Davis & Gary Lehrer
Page 27
https://www.gopens.com/Vintage_Pen_Parts/WatermanBook.php
