I tend to agree with most of the observations so far, that this is probably an earlier 20th century blade and Roanoa's Eritrean example kaskara is most compelling. The 'script' on this blade seems to be stylized interpretation much in the sense of 'thuluth' as found etched on Mahdist kaskaras, and may be intended to represent ancient Geez characters along with the apparant classical theme of the motif. The profiled head seems to correspond with ancient silhouettes on coins as Derek has mentioned, and possibly there may be some connection to some ruler of the ancient Axumite civilization that existed in Eritrea? The lion is atypical of the familiar and regally portrayed Lion of Judah seen on Ethiopian weapons and seems more totemic or allegorical.
It is important to note that in Eritrea the kaskara remains symbolically important as an element of status in costume as well as ceremonially used. A friend who is from Eritrea once lent me a video of ceremonial dances from his country, which was completely intriguing (especially to my wife who finally had to enter my domain to find out what in the world I was listening to!
A variety of edged weapons are used in the dances, several of which the kaskara ( which is never called by that term, only sa'if) was key to the gestures and movements. It does not seem that a sword from Eritrea would carry Ethiopian references despite the numbers of former Ethiopian population.
Best regards,
Jim