Ooooo! This is speculative (well maybe some of it), but fun. Alrighty then............
Revan 34 (I guess I think he/she has been living just a little longer than what most people think.)
Carth 38 ( I just don't see him any older than in the mid or late 30's at that time in the game.)
Mission 14 (Yeah, that was a givin' wasn't it.)
T3 (How would you really know, since they are machines. Just about every part is replaced over time through regular maintenance by the owner.)
HK-47 (^Same as above.^)
Exile 37 (He/she has to be in their late 30's by now, in this game, if they followed Raven before to the Mandalorian Wars.
T3 (Again, machine can't really tell.)
HK-47 (^Same as above^)
Go-To (^Same as above^)