What we ended up making was a desktop with the book and the map from the book laying on top. Then, we had the little man on his little mower sitting on top of the map.
The desk is just stacked square cakes (2 layers thick) covered in brown buttercream. A nice trick to use when working with buttercream is to smooth it out using paper towels. If you want a perfectly smooth finish, get a brand with no embossing work (like Viva). The kind we used on the desk had a nice pattern on it that, when applied to the brown buttercream, made it resemble worked leather. Simply take your paper towels and gently press them against the buttercream. This removes any knife patterns and leaves a perfectly smooth finish.
The book is also stacked cake, but the cover is made of fondant. We painted the front brown with food coloring and a paintbrush to give it an old, antiqued look. We also cut out some golden fondant designs for the trim and center of the cover. To make the effect of the pages, we made royal icing and colored it, then applied it to the edges, leaving obvious brushstrokes (which gives the effect of multiple pages). Finally, we cut a brown bookmark out of fondant and placed it to look like it was coming out of the bottom of the book.
The map is rolled fondant colored to be off-white/old and antiqued. Using the actual book map as a reference, we hand-painted it with food coloring and pearl dust. On top of the map is a figure (hand sculpted from gum paste, fondant, and modeling chocolate) sitting on a (storebought) toy mower.
For the finishing touches, we sculpted an inkwell out of black fondant and stuck a quill pen in it. Lastly, we wrote on the cake board: Celebrating *insert age* years of Progress."