Originally Posted by
ccdjg
It is almost certainly taken from Dennis Hiller's "Collectors Guide to Air Pistols", pages 151-153, where Dennis has somehow misread the inscription on a Belgian Simonon air pistol, dating from the late 1800's and lists it as a "Siptonon". L.J. Simonon was a Belgian gunmaker based in Herstal, Belgium, who had a number of airgun patents to his name.
Details of this pistol, which now resides in the collection of Larry Hannusch, can be found in the Encyclopedia of Spring Air Pistols, page 115.