The following is reputedly from a Gun Digest article “Going the Distance with the Sharps Rifle”.

The Model 1875 Sharps rifle incorporated patents by Rollin White and Nelson King. A Long-Range version shown at the Philadelphia Exposition was bought there for $300 by Colonel John Bodine. It remains the only surviving specimen, as no other 1875s were made. But Charles Overbaugh and A.O. Zischang, who had helped design the rifle, delivered a replacement.

Unfortunately, no year was given and very unfortunately no sources for the claims. For example, the "only one" claim has been soundly refuted, and diligent internet inquiries have revealed no patents by White or King that could be relevant to the Model 1875.

I have also heard that Hugo Borchardt had a hand in its design.  However, Borchardt did not join Sharps until 06/01/1876.  So his supposed Model 1875 association may have grown out of nothing more than the resemblance of the 1875's receiver to that of the 1878 Borchardt.  (Though that resemblance does lend some credulity to the claim that some Model 1875 tooling was reworked for the Model 1878.)

All in all, Bob, reproducing a Model 1875 could be another very worthy - and challenging - project.

Bill Lawrence

Another source of at least photos: vol. 3 of Roy Marcot's Sharps saga.

Bill Lawrence

Tom, at some point I’d like to give you a call.
Bob