Thank you Simon,
It is a perfect fit for the gap because the geomtry for the tree came out of the bench. There is a 1/4" gap all around as if it had been cut with a router bit.
The procedure was as follows:
Draw the bench and add the tree shape to it. The easy way to add the trunk of the tree is to copy the edges of one end using Ctrl+Move. Then I drew in the branches. The gap between the tree and the rest of the bench was created with a combination of Offset and Ctrl+Move--Offset for the branch portion and Ctrl+Move on the trunk. the cut out around the tree was completed with a couple of arcs on the back of the bench and the face representing the router slot was deleted.
Next I used the Unfold plugin on the tree to straighten it up. Then I used Joint Push/Pull on the surface to give it all thickness--3/4" in the case. To finish this up I filled in the inner faces with a few lines to heal the flat faces and a bit of regular Push/Pull through the top part to create the faces around the curves.
Probably easier to draw than build.