Your fully right jhsiao, the short bulb sac looks to be original, never seen one like this.
As Maja already stated, it looks to be an early Imperial 1
The Penhero site really is an amazing source of knowledge.
Sorry for my wrong conclusion, glad I've learned something new !
Francis
QUOTE(jhsiao @ May 20 2008, 01:18 PM) [snapback]616725[/snapback]
I'm torn:
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1) Using a sac that's of different size from every other TD or Snork would require an inventory of different parts just for a single low-tier pen. Not alot of sense financially.
2) However, from an engineering standpoint, I can see that there may not be enough structural support to have a long, slim #14 sac full of liquid extend into the barrel without a sac protector. Likewise, because the plunger is plastic, it may need additional thickness or length to make the pneumatic action without cracking (unlike the metal plunger). Without looking at the innards, I can't say.
Note the PenHero site linked above references a "bulb shaped sac." So it could be the original design.