Hi All,
The chances of this sword bearing a japanese blade are just like the chances of Saudi Arabia winning the world cup this year

Its almost impossible. These swords were primarily made in the towns of Hai'l and Al-Jouf. As for Hai'l, it was ruled by the Al-Rasheed's whom were allied with the Ottomans. They had no trade whatsoever with the British Empire, nor the British's allies in the region itself, the Al-Sau'd's and the Bani Hashim. Al-Jouf, was a town which was disconnected from the entire region, it was ruled by the Rwala tribe, headed by their sheikh, Nuri Al-Sha'lan, who had a price on his head by the high porte, and was mostly interested in raiding nearby regions than trade. The Ottoman army constantly besieged Al-Jouf, Rafha and Turaif, the strongholds of these northern tribes, which were constantly breaking off, declaring independance from the Empire. Such towns wouldnt appear pleasing to a merchant. Secondly, and most importantly, I wouldnt think that the British empire or its Japanese subjects would bother themselves into supplying blades into another region, accross the entire world. Basically, I see no chance of this blade being Japanese in anyway, except that it bears a very Japanese like blade. As Tim said, why cannot we see Japanese blades in the northern hemisphere of the world, regarding this subject, European blades of the past 200-150 years were by far, better in quality than Japanese made ones, and were highly sought after in the Arabian market, regardless of this demand, they were not that easy to find, throughout my saif hunting career, ive only seen one Nejdi style sword with a European blade, which bore a 1822 LC french blade, which was very nice sword BTW.
As for the age of this sword, I personally wouldnt think that its much older than 150 years, at the most. Its certainly not 20th century, as most 20th century saifs have longer, more curved blades, which are also finer. Of course, most of this is guesstimation, based upon my handling and viewing many arabian swords.
I just finished polishing the scabbard and hilt fittings, looks MUCH better now, after all the rubbing and scrubbing with that rouge. Ill post a pic tommorow.
EDIT: Just noted something, looking down the pommel, which was very damaged, I can see the end of the tang of the blade, and as with ALL arabian swords, the end of the tang is hooked. Now I do not think that the Japanese produced hooked tangs for their shin-gunto's or gendaito's