We learned something very important during this process. Epson—and we presume all other consumer level inkjet printers—pull in each sheet of paper just slightly different. A minute angle or a little to the left then a little to the right. We discovered this when we went to add the blind emboss and the red letterpress images. We would line up the sun and clouds perfectly and the windows and alcoves would be off. We then line up the windows and alcoves and something else would be off.
At the time, the process was very frustrating, however we learned about limitations and about how to overcome them when necessary. One exciting note was seeing how the letterpress overprint worked against the Epson prints. While the results were just a bit darker than the computer thought it would be it was great to see that it worked without being completely opaque.
We also learned that hardcore letterpress people were deeply concerned that we were trying to "mimic" genuine letterpress by using an epson and then a blind emboss. Fear not my friends; your craft is safe, this was just an experiment in printing and fun.