Here is the best picture I have which was taken before I bought the boat. I might be better off to simply move them to the outside of the transom than making extensions for them?
I would add the extensions first. Cheap and very easy to do. Here is a picture ................
1972 16 OB - C16B-63 - "Surface Tension" Resto Project
1974 16 OB - DMR16106017-B - "The Mule"