Thank you for reaching out to us. Can you show us a photo of your operator with the window open so that the arms that move the sash are fully visible? Once we can identify the operator, we can determine which handles are compatible with your assembly. Thank you!
Certainly, our return policy can be found here just in case. All orders can be placed directly on our website at your convenience!
We don't sell a T handle for a 5/16" spline. The 39-102 T handle that fits an 11/32" spline appears to be our best option. However, we don't have this in a light bronze color option, unfortunately. I am sorry for the inconvenience.