Sailor 1911 International and 1911 full size have 21K nibs while the 1911M comes with a 14K nib. A few times I've run across what appear to be 1911M pens with 18K nibs. Does anyone have any information on them? Since they don't seem to be available to the U.S. market, are/were they intended for the Asian market? How does the 18K compare to the 21K and 14K nibs?

Hrm... this one stumps me... I think I have only ever encountered 14K and 21K variants... Could the 18K nibs be on the older series? I can't see any offerings in the current Sailor line-up which have 18K nibs.

I honestly can't tell the difference between my 21K Pro Gear nib, and my 14K Sapporo nibs - they are all just very firm and lovely to me. Helpful stuff, I know.