Hi All, sorry for the delay in writing, New Years involved some travel this year and a lack of time on the computer over the last few days.
I'll try to cover each one of your notes, I really appreciate all the interest!
Ibrahiim,
Well I would agree that your idea is a bit more fanciful.

I should perhaps explain a bit more detail about what is meant by a "Greek cross" (please forgive the ramblings of someone who took a lot of Medieval art history some years ago!).
The Greek cross refers to a cross where each arm is of equal length, as apposed to the standard Latin cross with a longer lower arm. The various Coptic crosses and the Maltese cross are a variation of the basic Greek form. Transmission of the form does not need to rely on pilgrims, Greek iconographers and scribes were well established in early Medieval monastic communities and if my memory is correct, one such individual was also involved with the illustration of the book of Kells. My point being of course that there was a lot of interaction between the Byzantine tradition and Western Europe. So I don't think pilgrims and the sword blade going to Ethiopia is really something that makes a lot of sense. There are also a few other swords, some still in Europe carrying the same cross.

For example "Handbuch Der Waffenkunde" notes the mark as being used in the 13th and 14th century in Italy.
The second, smaller mark has also appeared on one other example thanks to some kind assistance from another forum, in this case on a 15th century sword, but one with a very likely older blade.
Teodor,
Thanks for bringing forward another possibility in terms of a potential vector. You are of course entirely correct, the Tuaregs had a huge influence on trans-Saharan trade, occupying quite deliberately territories through which caravans passed. Cyprus and Malta get more attention, but you are absolutely right, there is no reason this could not have been transmitted via Morocco or any other port on the North African coast.
Jim,
Great post, just to cover a few points and more or less sum up where we stand now...
This seems to likely be a late 14th, early 15th blade of Italian manufacture. The cross is possibly a consecration mark, while the second mark is harder to pin down with a date since so far only one other example has come to light and that may well be a composite piece, however even that is at least 15th century.
The mounts to me are likely 18th century, using the known 1830 examples to compare. There is no way to know if these were the first mounts the blade had, but due to the shortness and extensive sharpening I tend to think not.
Of course it is only speculation but I would not be surprised if the blade found its way into the interior by the 17th century.
All the best,
Iain