PB,
An interesting project.
Let's say for arguments sake you wanted to make a wood copy of a mini mag light .
All the external dem's would have to be a little larger since wood is not as stiff as aluminum, and if you sit on it most likely it will shatter and leave splinters in a hard to treat place.
I suggest some kind of very hard wood. I have no expert skills here, but if memmory is any good at all, look up rose wood. I reserve the right to be wrong.
A wood body for the battery tube is a trick to make. Im going to assume your talking about a 2xAA device. You can buy long enough drill bits and make a deep bore for the 'handel' part. For D cells you might have to go to MSC and order something very expensive.
The head might have to be a little thicker as well. Make it a click style rather than a twist. Geting wood to hold threads is not an easy process.
As for the brass parts, any good jewlery maker can fabricate that for you. I suggest rechargable batteries so the unit won't be opened very often.
Since Im in the middle of a desert right now and have no access to machine tools, that's the limit of my ability.
Hope all is well
Jack Crow in Iraq