I am aware of the fact that 49mm "Skylight 1A Filter" glass is the best for the shutter window but does anyone have any suggestions on what kind of glass I need to use for the flash and counter windows. This is my first attempt at this so everyone's input would be greatly appreciated. Also, how should I mount the filter glass?? Do I remove the metal rim around and mount it flush or do I mount them on the outside of the box?? Sorry the questions seem so dumb but as I stated, this is my first attempt.