Sharp ELSI MATE EL 315 Calculator From Caterpillar’s 1981 annual business meeting at the Davenport Iowa Plant. Back of cover says “1981 Annual Business Meeting Davenport Plant” with the old Caterpillar C logo. 1 - 100 - 1000 Calculator has letters LC scratched in upper left corner above the display (see pictures). There are also hairline cracks on the back of the calculator across the screw holes. Otherwise, this is a real nice little calculator with lots of history!