z Press Button Knife Co INVINCIBLE antique switchblade

Vintage Press Button Knife Co INVINCIBLE model switchblade made in Walden, NY sometime between 1912 and 1923. The knife measures 4 7/8 inches closed and 8 5/8 inches open steel liners. The blade is marked PRESS BUTTON KNIFE CO WALDEN, NY on the tang and the backside is blank. The blade is about 90% full and shiny with light scratches.  The picked bone scales are in very good condition with no cracks.  The knife functions well with the blade tip deep in the well closed, opens fully when button pressed and locks open with some up and down and side to side movement at the tip. Average lockup for these old knives and rattles if shaken when open. These open best if you use your thumbnail to press the button. This is a nice working example of a 100+ year old American made switchblade. VG+ condition.