Press Button Knife Co #1000 INVINCIBLE antique switchblade knife w Etch

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 with steel liners. The blade is marked PRESS BUTTON KNIFE CO WALDEN, NY on the tang and the backside is blank. The blade is mostly full at about 97% with patina, light scratches, light pitting and spotting and you can still make out part of the original acid blade etch! You can easily see "BLE" and the fancy design on the ends of the etch and if you look really close and turn the blade to the light you can make out the "C" & "I" and bits and pieces of the "INVIN". Hard to find these with any of the original etch intact because they were so fragile. The picked bone scales are in very good condition with no cracks.  The knife functions well with the blade tip below the liners closed, opens strong when button pressed and locks open with about 1/8" up and down and little side to side. It does rattle if shaken with the blade open as most of these do. This is a nice working example of a 100+ year old American made switchblade with some etch! VG+ condition.