The following image is available from the "William Gray Purcell Job Files" digital images database served by the IMAGES system at the University of Minnesota Libraries.  The thumbnail link goes directly to their access and use statements for the image.  A (usually) higher resolution image can be downloaded from the citation display page; such files may show highly useful detail, but are often 200-300K in size.  Because their web site is a separate resource, the link here opens a new browser window.

Elevations and other detail