Hi 'Nando

,
I'm glad you like it and thanks for your input. Yes, I too believe it is a lost wax casting. I wondered whether this was Ashanti, I have read that families owned similar 'boxes' to store gold and other precious items. There are many examples of Ashanti gold weights......made from brass/bronze these pieces are cast (lost wax) in many shapes (including zoomorphic, weapons, figures etc) and weights. Used on balance type scales to weigh gold dust/nuggets.
The animal designs seem to portray a turtle/tortoise and a lizard/crocodile. Whether these are 'guardian' spirits or 'good fortune' or protective icons, I have no idea.
The rounded body seems to have symbolism ....the sun ? I cannot work out the possible meaning of the fan shapes in the border ....simplified tufts of grass/reeds ? The linear design of the lid is mysterious too.
It weighs approx. 3.5 kgs ....so is no lightweight.....the 'box' seems to be cast in one piece.
I agree, Tim's great knowledge of casting may be able to shed more light.
Kind Regards David