Well, we've just seen a tatar sabre with a golden dot in another thread - I seriously doubt that it has anything to do with Abbasids. There is one sword on e-bay right now (and I don't discuss it
) that has dots, and explicitly dated from XVIII century.
Concerning "swords of companions", it's usually impossible to prove that something is not of VIIIth century, but usually the burden of proof is on the person claiming it to be of VIIIth century.
Concerning mamluks and their relationship with Muhammed, one has to remember that circassian mamluks and even some later georgian mamluks (Ridwan bey) claimed descendancy from the companions by telling stories about some of the companions "getting lost" and "appearing" in Circassia. Actually few muslim leaders did not claim to be sharif, sayyid or at least in some relationship with Umar. My favorite example is that of my friend, Usupov, from Nogai nobility. Officially he descends from "Abu Bakr, Kirei ibn Dok - Caliph of Egypt and other countries". The problem being that Kirei is a tatar tribe, and Dok means fat in turkish
.
Another great example of how important religious relics are is example of judaim - when it was split in between of chasids and misnageds, the first ones suddenly "inherited" the staff of Moses (naturally the ones who presented it claimed the descendancy from Moses' brother) !