My dad will be 75 and I am making a sheet cake. He is a retired carpenter and loves working with wood. Any suggestions for a cake of this nature? Thanks!

How about making the cake look like pieces of wood. Then make a gumpaste hand saw and have it cutting the wood.

Maybe this cake could give you an ideas, it was made for Addie on CC spanish forum

http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1654723

Here's a neat idea

http://coolest-birthday-cakes.shippony.com/images/theme/construction/construction-tools/specialty-cakes-02.jpg