Casement window operator replacement
Thanks for reaching out! I believe our 39-315 Truth Dyad Operator would be a better replacement for your existing operator; the opposite handed version is part 39-316. This has a 5" arm as well but I do not believe the difference between the dimensions would impede the function of the window. If there are any issues there are two options we can provide you with that will help you make the modifications needed to complete your window repairs.
You may also need to replace the the bracket as well. To replace this one, you'll need the 39-546 Truth Snap-Stud Bracket. The 39-316 would likely use the 39-545.
These operators are compatible with the 39-114L non folding and 39-205 folding crank handles.