COLONIAL SHUR-SNAP Fishtail White late 50s Gen 4 bowtie switchblade knife

Vintage Shur Snap fishtail (bowtie) switchblade with white synthetic scales made by the Colonial Knife Co of Providence, RI in the late 1950s, likely 1956-58. It was designated the model #1800CB and measures 4 inches closed and 7.25 inches open with brass liners, steel bolsters, button, safety & pins. We can tell it's a later 4th gen knife by the large domed button. The carbon steel Saber grind blade is mostly full (about 96%) and shiny and has been cleaned and front grind line mostly lost in the process. The tang is stamped SHUR SNAP over Colonial over PROV USA. The white colored synthetic scales are in nice condition with a little shrinkage at the bottom (back). Operates well with blade tip sitting deep when closed, good snap and average lockup with about 1/16" up and down at the tip. Safety works. G+ condition.