This is excellent Jens, and thank you so much for not only taking this topic to another thread, but for the beautifully done illustrations and labeling them. This will give us a core of known markings that I hope we can add to as more examples and evidence become known.
Regarding the umbrella marking, what is the alam, significance? Sorry I keep forgetting these things but cannot locate in resources at hand. I think you are right that these umbrella stamped markings were used by rulers or extremely high rank court officials possibly, but still wonder if they might have significance as quality marking, i.e. of the quality of a blade made for a king etc.
As I mentioned on the other thread, there seems some variation in parlance for the use of the term armoury vs. that of arsenal. In the definitions I found, the armoury would have been a storehouse for weapons and such material, but apparantly may have included captured or 'trophy' weapons collected by the ruler or his forces in battle. This is well illustrated in the instances of the swords of Crusaders taken in battle that ended up in Alexandria and finally Istanbul. These weapons were often marked or inscribed, and quite possibly the same practice occurred in India in many cases.
The arsenal seems to have included the additional feature in addition to being a storehouse for weapons , as the armoury, that it often included a factory to produce weapons. It would be interesting to consider if an 'arsenal' might have a staff of makers or might they have used neighboring makers on an 'ad hoc' contract basis. As mentioned, markings were not always added, and perhaps weapons produced outside the arsenal by private contractor might have received different treatment as for markings. It does seem the weapons might have had a numeric code or such for benefit of payment or contract of the contractor, and we have seen such numeric instances on many weapons.
Concerning the fact that swords do seem to more often carry markings, presumably from armouries (or arsenals), makers and the fact that daggers do not usually carry same may derive from the probability that daggers are much more 'personal' weapons. Since these would seem more often privately purchased and outside the perview of the armouries, the only markings would seem of more personal nature rather than these stamps.
The book you note on Rajasthan sounds very interesting, and it would seem that it may hold a lot of important related information. This area was, if I am not mistaken, a key manufacturing region that was key in producing weapons especially in the 19th century (to present time actually). I believe the armouries you have identified are in the Rajasthan region as well if I am not mistaken.
Very much looking forward to more input on the topic of markings found on Indian weapons and hope that everyone will contribute. This subject has never been even close to adequately addressed in studies of Indian weapons and it would be great to see to the outstanding core of knowledge and resources here resolve that!
All the best,
Jim