DocNib sent me this cool shot of 4 pens with unusual filling mechanisms.

From left to right in the pic:
1) Zain-Crocker "Hatchet-Style" Filler
2) John Holland Hatchet Filler
3) Jaxon Side-Button Filler w/Locking Ring
4) Held (Janesville) Twist-Lever Filler

Thanks DocNib. Is there a story behind that name?

- Mark