Nick wrote:
A strange request perhaps.
SWMBO has tasked me to convert a clean, blown, natural ostrich egg into a
container for a specific purpose.
The egg is approx. 6.5 x 5.0 inches (165 x 127mm) and 2-3 mm thick. Makes
the eyes water just thinking about it!
Can be cut either longways or sideways.
As this is a one-off and we only have 1 egg, I would like to get it right
first time. Also only a week to produce the finished article, to include
hinge, fastener, turned base etc.
Any experience or thoughts on such stupidity please?

I have a decent range of hand & power tools but have never worked on
anything this fragile.

Mark the cut with a pencil. Hold the egg in a bed of cloth or white
sand Cut around with a fine-toothed saw with a good "set" on it. Do
not try to push the saw through, just let it rub away. Go right
around, turning the egg as you go, without cutting right through
the shell, until you find the saw going through, then carefully
finish off. Don't force the blade, don't let is waggle about. I
wouldn't use any power tool, and use something with a decent
length of blade so that it cuts to a good line.