Hi Magnus
Interesting full body profile on the shells, not just a belly protrusion.
Especially the tumba, that one is all belly
Shells/hardware look strong and of quality construction.
Wood looks like what is known as Ash, which is a desirable conga shell stave material, because of its stability, strength to weight ratio, bending and gluing properties.
http://www.hardwoodinfo.com/species_guide/display_species.asp?species=ashDoesn't look like you have a lot of room to tune them up anymore, as all lugs look pretty well bottomed out, and skins pulled way down, so if you buy them, a new set of skins may be in your future.
...But, that would be a small (additional) price to pay to breath new life and sound into them.
~Joseph