My original post showed a drawer added to a galley base cabinet. Since that posting I have modified the drawer to gain some extra storage space.
Here is a general view of the drawer. Originally it was not as deep as the cabinet because there is a drain pipe running along the back wall. I realized I could make an extension that would ride above the pipe and take advantage of the full depth of the cabinet. The next picture shows the detail:
Here you can see the little extension at the back of the drawer. The drain pipe (black) can be seen in the background. It's really just a small box screwed to the back of the drawer with enough space below to clear the drain pipe when the drawer closes.