This item is Discontinued and is no longer available. 
Replacement: Use the Square Button 8 inch arm Operator 0531108 LH & 0532108 Track

Andersen Roto-Gear Casement Operator with Round Button.
1945 to 1960.
Bronze Finish.
Was available in 8 inch and 10 inch arms.
Markings: 7073A 


Priced and sold each.

Written Article: Andersen Casement Window Operator Replacement
Video From Andersen: How to Replace Straight-Arm Operator

Related Andersen Window Parts:
0531012 - 7-1/2” Bronze Right Hand Andersen Casement Operator With Handle
0531008 - 7-1/2” Bronze Left Hand Andersen Casement Operator With Handle
0531108 - 7-1/2”  Bronze Left Hand Andersen Casement Operator With No Handle 
0531208 - 7-1/2”  Bronze Left Hand Andersen Casement Operator With No Handle 
0531112 - 7-1/2”  Bronze Right Hand Andersen Casement Operator With No Handle
0531212  - 7-1/2”  Bronze Right Hand Andersen Casement Operator With No Handle
0566012 - 9-1/2” Bronze Right Hand Andersen Casement Operator With Handle
0566008 - 9-1/2” Bronze Left Hand Andersen Casement Operator With Handle
0566112 - 9-1/2" Bronze Right Hand Andersen Casement Operator With No Handle
0532008 - Track only  
0536011 -  Handle only