Purchased a 1966 14' runabout late last year. It is made by MFG and the model is a Mustang. It has had a deepth/fish finder attached to the transom. When it was removed the mounting holes were never patched. The wood is rotten in this area and when it freezes here it is causing more damage. Is it alright to just do a partial repair to the transom in this area? Any help is greatly appreciated.