Hi Shane - yes if you have a trimmed surface you can "untrim" it to restore the full original surface.

To do that, select all the trimming edges for one boundary loop of the surface (like around one hole), and then hit delete. You can grab all edges of one surface quickly by selecting one first and then doing a Select All (Ctrl+A).

Here is one post that describes untrimming in more detail:
http://moi3d.com/forum/index.php?webtag=MOI&msg=444.4

Also here is a more complex mini tutorial that talks about using untrimming and re-trimming to repair an object that had a boolean done to it in an incorrect location:
http://www.moi3d.com/forum/index.php?webtag=MOI&msg=446.17

- Michael