Writing on a Euro blade mounted in sboula
 

Just won the auction for this. The blade looks like a real sliver of a thing but it appears to have some writing on it. The seller says it reads NOABN. Any idea what it might mean? I'll clean it up and take better pictures when it arrives.

A most intriguing Morocco s'boula which as noted, has been mounted with what appears to be a European cavalry blade very cut down and severely re profiled.
These letters are not a word in my view, but most likely an acrostic of some phrase or invocation, as sometimes occurring on East European blades of mid to latter 18th into 19th century. These kinds of motif were much used in earlier centuries on blades, but traditionally maintained quite late along with elaborate flourish and motif.

These rugged type examples reflect the traditions of certain weaponry as ethnographica which has remained in many cultures into present times.

Interesting, thank you. Both sides of the blade appear to have writing on it so hopefully it won't all be cryptic. The rust on the blade looks very recent, I bet it was cleaned in the last decade or so and then allowed to rust.

Given the Moroccan context of this weapon I would be inclined to suggest this blade is likely a French one of mid to latter 18th c and the style of the lettering seems much like blades often referred to as 'Cassignard'.
I do not have the book by Buigne at hand, but if I recall such inscriptions can be seen there. These were often accompanied by various floral and astral motif and associated with artisans in Nantes.
As with regions here and well into the Sahara, blades from the French occupiers often were 'recycled' into native weapons. These s'boula more commonly are found with French bayonet blades, so this one is somewhat remarkable.
I would think its present 'incarnation' may well date from 1860s into latter 19th optimistically, but recycling was virtually unlimited and could extend into 20th. Still, the blade seems as noted and interesting to see this use of it.
Typically such sabre blades ended up in either the sa'if known as 'nimcha' or often in the Manding sabres of Mali.