Question for leather workers?

I am thinking of having a go at making River's diary from Doctor Who.

I'm planning on using vegetable tan leather for the tooling, but was looking for advice on what thickness would be advisable for this project?

Thoughts?

[FONT=Arial]Birdie,

I would think 3-4 oz. leather would be good for a project like this.

Paul[/FONT]

I agree.. Just to give you an idea, belts are made using 8 OZ and
up depending on what the make is.. If it were me, I think I would try 4 first..