Actually, I found the answer to my question, indirectly, by digging around in this group. Anyway, the file to be modified is:
/opt/onebody/app/models/printable_directory.rb
Lines 181-183
def image_bounds_width
bounds.width * 0.6
end
I changed bound.width*0.6 to bounds.width * 0.9
Now the pictures are bigger.