Help with Blank Generic Certificates

I've been cataloging railroad certificates for twenty years, but have encountered only a handful of blank certificates. Why so few?

A large number of printing companies produced blank stock certificates. I call them "generic certificates" and they were usually adorned with images that might have been used by different kinds of start-up companies. Typical images included railroads, mines, oil wells, eagles, and flags.

A long-time German correspondent just sent me this lithographed example with a freight train moving right to left. Collectors have no doubt seen images like this a thousand times.

This certificate got me wondering how many more blank certificates might be out there. I simply don't know. I'm guessing that most were discarded a century ago.

I would appreciate hearing from you if you own ANY completely blank generic certificates. (With the possible exception of certificates with oil-related vignettes, all varieties of generic certificates were used at one time or another by railroad companies.) Please send 200 dpi scans to my regular email address reachable via the Coxrail web site.