Looking For A Pattern # or Identification On This Large Tested Pen

[herbva]

This one just came my way and I can't find it in any of my reference books. (It is a bit large for a pen, but I don't know what else to call it.) It measures 3 11/16". (Not quite 3 3/4", but maybe I am being to precise.) I assume the scales are celluloid, but I'm not sure. Any info would be appreciated.

[knifeaholic]

It is a 4257.

Sometimes referred to as the "Office Knife". The spay blade was for use as an ink eraser.

[cudgee]

You blokes are just too good. Your knowledge of knives knows no bounds.

[herbva]

It is a 4257.

Sometimes referred to as the "Office Knife". The spay blade was for use as an ink eraser.

Thanks Steve! I have owned a few "office knives" in the past and it didn't click in my pea brain. I guess I just assumed they all had the "Office Knife" engraving on the scales or the name of some company or business. I think this may be the first plain, unmarked one that I've seen.