Most interesting developments here with the mystery of German blade presence in these Omani swords, whether original trade blades or examples copied by Omani artisans. First of all, the name STAMM was a well established sword blade producing family there, indeed even slightly earlier than the 17th century, the earliest being Clemens Stamm (1580-1610, listed in Bezdek p.154). Others were Peter (1680-1700, who used the marking depicting Jonah and the whale); Abraham (1764-1770); Wilhelm (1778-1820).
There is indeed a pata listed in Pant ("Indian Arms & Armour", #217) with a blade by M.Stamm (captioned by Pant as Abraham Stamm, Solingen, 17th c.). It is well known that the Mahrattas heavily imported blades for thier swords in these times, highly favoring German blades over the British ones. German blades entered these areas by the thousands, presumably the source of the 'Alemani' term for swords carrying them (usually sabres).
While unclear whether the '1708' on this blade is indeed a date, or perhaps one of the many variations on so called magical numbers is hard to guage.
As indicated, the use of these mystical numbers such as the '1616' on the hollowed smallsword blade (clearly 18th century as per the form) and the name 'Sahagom' which was a 'brand' used by Solingen on blades headed for Continental markets, this could correspond to the 17th century attribution for Stamm. Whatever the case, and whichever Stamm might have been the maker, this is certainly a 17th century German blade.
The 'PDKG' is less attributable, and these kinds of four letter monograms are found in numerous variations. In the case of Hungarian sabres, typically made in Styria or Italy but of course Germany as well, the letters 'IPZD' are a recurring combination. It is often believed that these groupings which exceed the typical two letters presumably initials, may well be acrostics for phrases or slogans etc.
As your research has shown, the 'PDKG' has been found on other apparantly Solingen sourced blades of the 18th century, one to European markets and the other to India, which again, we know was receiving German blades in the 18th century, these combinations seem identifiable to Solingen.
As has been well supposed, German blades were well represented in Arabian regions as well as enrepots throughout these trade networks through the 17th and probably into 20th century.
Excellent examples shown and outstanding research!!!! You really have this topic moving Ibrahiim, nicely done, thank you.
All the very best,
Jim