Here are a few examples of how others have treated their letterpress trays:
I love this lovely inky one on Taylor Groneck's blog
Greenwich Letterpress featured on Design Sponge
Jennifer DeDonato at Colorfly Studio
Kristin Perkins displays her jewellery.
Update: I just looked at this post next to yesterday's one with my full stops collage and realised my love of repeated forms and order is really showing at the moment! OCD anyone?