Hi Marc ! Nice to see another takouba lover on the forum !
The one with the brass hilt has a nice blade, albeit sharpened alot, it could even be an European trade blade, considering the regularity of the fuller (don't quote me on that though !). The hilt is really unusuam and, as is often the case, most likely later, though it does show some wear. My guess would be second quarter of the 20th century or slightly later. Indeed, I don't think aluminium was widly available in Africa before WWI, and this style (heavy brass base, with copper and aluminum, and triangular shapes), although I can't precisely pinpoint it, is very reminiscent in my opinion of what can be seen on modern decorative daggers and short swords from Niger (see post 4 here :
http://www.vikingsword.com/vb/showth...ghlight=agadez), the chape of the sheath is also very reminiscent of what can be seen on some small knives from Agadez (see mine for example :
http://www.vikingsword.com/vb/showthread.php?t=26194). Niger could thus be an option for the mounts, in my opinion; in anyway, that's a nice "modern" twist on a traditional design and I like it !
Onto the Tuareg one (the design and ornamentation of the guard definitely look Tuareg, at least according to what Morel wrote on the subject), it is indeed a rather recent one (post ww2), mostly given the shape of the pommel (very flat), however the blade is definitely not one of the ugliest I've seen, with a clear and rather regular fuller (as opposed to the symbolic grooves you can see on some examples).
Finally, the single-edged, or Aljuinar as Jim rightfully pointed out, is indeed a textbook example of saber-like takouba that Iain Norman described as being from Nothern Cameroon. The blade on this one is really interesting, is the close-up you posted a repair ? Do you think it is forge welded ?
Anyway, thanks for posting those nice swords, and don't take anything I wrote at face value, as I am myself just a mere beginner in the study of those amazing weapons !