Vintage Crank Mechanical Underwood Leader Adding Machine Model 67

#834632
1930s or 1940s?
3 by 3 numeral grid above the zero.
Heavy with a rounded shape.2 function keys Left says "X Rep't" (repeat?). Right key says "No. Total"
It's frozen up from sitting idle for many many years. It has some movement, but I wouldn't want to force it.
15 1/2" X 8 1/4" X 9 1/2"