Looking for ten of this casement operator

Hey Jim. I believe you might have either the 39-031 and 39-032 Dual-Arm Operators, or the 39-155 and 39-156 operators. The difference between these two pairs of mechanisms is the length of the link arm. See the diagrams below for reference. Measure the length of your operators' link arms to see which set matches what you need. In either case, for new handles and covers, see the 39-114L and 39-107, sold separately.

Dimensions for 39-031

Dimensions for 39-155