MADE ITALY INOX 21cm Italian Ackermannchen Style Black lockback automatic knife

MADE ITALY INOX 21cm Italian Ackermannchen style black automatic knife made in 1960s or 70s in Italy. This style  of knive is often stamped Ackermannchen and I don't know of any other name for the style, so I'm going with that and as far as I can see the markings are the only difference. The knife measures 20.7cm (8 3/16 inches) open and 4 3/8 inches closed with brass liners and nickel silver rectangular button and safety cap. The swedge grind blade is 100% full with the original finish with some light scratches and the ricasso is stamped MADE ITALY INOX and the reverse is stamped PATS PEND. The black synthetic scales are in good condition with one tiny crack by the button and some scuffs from handling/use, but not bad. The knife works great with the blade tip sitting deep and centered closed, strong snap and very good lockup open with less than 1/16" movement at the tip. No rattle if shaken with blade open. This is a backspring release knife so you press on a grooved tab on the exposed backspring in the wrap around handles. Safety works. EX+ condition.