Bob - fortunately I've got the insert out of the cabin sole home for refinishing. I've taken a photo and included annotated stickies on the picture with dimensions. This assumes that you have the same cutout, located in the same place. The insert measures 15.5" x 58.375". The two table leg holes cut in the insert are 2.25" diameter. The forward hole center is located 9.375" from the forward facing edge, 8.125" from the port edge (7.375" from stbd edge). The aft hole center is 21.0" aft of the forward hole center.
Here is a link to a PDF file that shows pictures of the table insert points when I documented my bilge pump install.
Rhapsody Electric Bilge Pump Install and here is a photo of the cabin sole insert with the annotated dimensions:
[This message has been edited by Rhapsody #348 (edited 04-17-2008).]