I agree on the lock. I am new to collecting, but I am an old hat at determining age.
Hopefully with the added info someone here with more "knife years" under their belt can help you pin point at LEAST a region on this planet.
The match strike, and blade shape are confusing. The blade looks American, the strike English, the scales Japanese, but the "tone" looks Paki. I really doubt it is a Pakistan knife tho. Try to look more into the lock to narrow it down.
Age I would venture a guess at 1950's-60's, Just a guess...
Real cool knife no matter where it came from.
I'm following this to learn along with you.
WTB Kershaw 2120 MACHO Lockback Parts knife
I need a pile side scale. THX!