I didn't copy the same tex to the outside because this wouldn't really make sense since you have an inside (with the lockpicks in it) and a blank outside. If you would fold it together you would only see the leather outside.
I fixed the iguana stick, now it has 87 vertexes. Can't really go any lower unless you make the onions/tomatoes into squares or remove a part of the model
87 is good, but I can't open your kebab.3ds because of "Improper file format" error. Fruit opens normally. Is it my personal trouble or the file is damaged?
P.S. low-poly modelling has a lot of tricks to lower the polycount. I can show the main one.
If it small enough, you will never note that there are just 4 vertexes in this stick
Optimization is a creative process. Think, what will be visible and what won't be and cut the excesses.