Good to hear of the interest in your work and the genre as a whole. Iodine eats fairly rapidly through wood so unless there is a glass on glass seal the boxes and their metal hinges are going to not last long. Also if the wood gets laden with iodine then controlling the amount of exposure to the fumes gets even less precise. Mike Robinson did a nice set of boxes in the 19th century french style – http://www.cdags.org/2011/07/20/french-revival/ – which used a square glass dish made of glass sheets glued together, which makes finding the right size dish not a problem.
If you want to make high-quality boxes, I honestly don’t think you have much choice but use glass, especially if you are selling to people who are also using bromine. The problem with using wood isn’t only that the chemicals will eventually destroy it, but that hard wood simply doesn’t have a tight enough grain structure to prevent the fumes from escaping.
One option for you would be to ask the customer to do their own grinding. It takes a while, but anyone can do it.