In my opinion the dial looks to be refinished. It is not generally seen that a dial made for a watch circa 1917 would have "Swiss" printed at the 6 position. I believe that this was reserved for watches made after the 1950's. At the very least the dial is refinished for this reason as well as a few others. The dial is too clean without any signs of patina, wear, oxidation or watchmakers careless scratches. The cases on these early hinged watches were not well sealed and it is never seen that a watch even in "Unused" condition would not show obvious evidence of age.
As for a replacement dial, it is possible but likely to be simply a refinished stock original plate. If it were a replacement dial (and it could be) it was still refinished in my opinion for the reasons listed above.
I hope that this helps. Not sure that this is 100 percent accurate just an opinion.