blade looks a lot like a british 1796 light cavalry sabre hatchet point blade that napoleons troops feared so much they tried to have it outlawed, because of the fearsome cuts it made. many other countries emulated the style. (the point is supposed to look like that)
a lot of 1796 sabres were given to the portuguese by wellington. maybe manuel was portuguese? part of the inscription seems to go under the grip bolster/scales & the full tang construction may mean it was cut down from the pommel end.
(the brits themselves feared the sabres of the indian troops they faced in later years, only to find they were recycled (like your one?) 1796 LC sabres, the main difference being the indians sharpened theirs where the brits by then were indifferently sharpened & dulled in their metal scabbards by drawing/reinserting alot.)
north africa seems to be home to a lot of re-handled european blades.
as always, dimensions, blade/hand grip lengths, widths, thickness, weight will help. see attached. comparison only valid if dimensions fit
1796 blade=32.5-33 inches.
heck, it could even be mexican/spanish colonial with a european trade blade -
See This Linky to another thread here
1796 LC sabre photoshopped comparison: