Casement operating gear mechanism on Eagle Axiom 11

The crank gear action and arms need replacing. Crank handle and cover is fine. Etchings on the arms of crank read "6D O16S AMS on arm that connects close to middle under window, and S-1081-66 R" on part that connects under hinge side. The arms work fine, but it looks integrated with the gear mechanism. Lock latches are fine. Do you have this part or know where I can find it. The window size is 36x54. Thanks.