San Juan Drumheads

Where can I find some good photos showing the artwork in the original San Juan drumheads?
The pictures I have found so far all fail to show the artwork in the center. Apparently it was done on paper that became wrinkled behind the glass, and in all the pix I have seen the light reflects off the wrinkled paper and obscures the actual picture. You can clearly see the lettering on the circumferance, the "toilet seat" banner outline, and the name of the train....but not the picture in the middle.
It is clear from what I have found that there were at least two different drumheads for the San Juan, in addition to the Shavano drumhead that apparently was often used on the San Juan. The pix I have seen show at least two different styles of banner at the bottom of the "toilet seat", and two different styles of lettering for the name "San Juan". But none of the pix I have seen shows the artwork clearly. I have seen one charcoal drawing made from a photograph that vaguely shows some artwork, but not only is it vague but it is unclear how accurate it is.
Anyway, all that being said, can anyone point me to additional pictures, especially ones that show the center artwork, and if it's in color, that's even better.
Thanks in advance.