Stefan --I already replied by e-mail to you and answered your questions. Did you not get that?
I consulted with Alan Myers, who is the world's foremost expert on Jones. To give you that answer again, with some more detail, all as provided by Alan:
This is a Jones pattern 'R' from the early Seeland period c 1876. There is no pattern letter engraved on the movement.
The first Jones lepine movements appeared after serial number 19,000, so anyone wanting a lepine before then had to put a savonnettemovement into a lepine case.
All the early Jones movements were shipped as complete movements to America, where they were cased. We know of several of these early Jones savonnettes in American lepine cases and they are known as ‘sidewinders’ because the winding stem is situated at 3.00 o’clock. During the Seeland period, movements were cased in Switzerland.
This example is interesting because the dial has the numbers(and inscription) rotated though 90 degrees so that the winding crown is at12.00 o’clock. Being a savonnette movement, the seconds dial is at 3.00 o’clock.
We can only assume that Seeland ordered a number of special dials and produced a batch of these ‘savonnettes as lepines’. They would have been cased in Switzerland, probably in Shaffhausen.