this is just a first impression and we don't have enough data till now. I think for a small firm like Schüler this are a lot of guns, maybe 585 a year are to much. in the 1920s in special all had very bad times. I don't know what Schüler did 1914 -18.
other firms in this size like Collath make things like signal flare pistols and it seems they stampp it with the own SN so the post war sporting guns have a very high number without connection to the pre war years .
Schüler make the Reform pistol and the unique "Scheintod" pistol

and its possible that this little pistols are part of the serial numbers.