I am sorry I did not report back for all those who helped me before now. I had to replace the original Robalo nav light. It was corroded at the lower end with no electrical connection to the light. I had bent a conduit to the correct length and angle, but I could not remove the connections at either end of the original and make them work.
So, I purchased a Marine System Fold Down 25" stern light. It's base was the correct width and size to attach it to the windshield frame. It works for a nav light as well as an anchor light. I wish it was taller. There is room to move it up the windshield center post, if it becomes to much light running at night.
Thanks for all the comments and assistance.