Press Button Knife Co #1000 INVINCIBLE antique bone handled switchblade knife

Vintage Press Button Knife Co #1000 INVINCIBLE model switchblade made in Walden, NY sometime between 1892 & 1914. The knife measures 4 7/8 inches closed and 8 1/2 inches open with steel liners and nickel silver bolsters & button. The clip blade is 1/4 inch short, but otherwise pretty full at about 95% and shiny with light scratches and marked PRESS BUTTON KNIFE CO WALDEN, NY on the tang though it's hard to read because of pitting and the backside is stamped US PAT 470605. The dyed jigged bone scales are in very good condition. The knife functions well with the blade tip deep in the well closed, opens strong when button pressed and good lockup with less than 1/16" movement up and down and 1/8 side to side at the tip. Does rattle if shaken when open as most of these 100+ year old switchblades do. VG+ condition.