Thanks for the kind words Dom - I'm no expert just an enthusiast.
But I can give a few comments.
This looks like a newer takouba - probably the entire package dating from the 1970-1990s. Which would fit into when you got it.
The blade is probably older - it looks nicely made with well done moon stamps.
This style of pommel with the squared off edges on the stacks is indicative of newer mounts.
The same goes for the triangular scabbard mounts, older mounts have brass rings.
As Dom mentions, these are quite often re-hilted and fitted with new scabbards and leather work. So in short saying the sword is likely 1980s or 90s in its current state is not to say pieces like the blade are not significantly older.
Tuaregs as far as I'm aware still carry takouba as part of daily life and costume. Particularly I think for important social events such as camel markets. But no doubt you saw this yourself in Niger!
All the best,
Iain