On mine I just guessed a bit, and went from there. IMO the wand boxes are harder, and more time consuming to make than the wands.
Another member here had a great tutorial on making them and I will post the link as soon as I find it.
I think a few members here have screen used ones.
Keep in mind that there where different sizes and shapes so pretty much anything will work.
The ones I have from Nobel Collection range from 14.5" to 15.5" long
3.125" wide and 1.125" high
Thanks for the help, I'm not necessarily going for screen accuracy as these are mostly Christmas gifts for my nieces and nephews and I know they are going to get beat up... just going for a bit of that holiday WOW factor....