All of the knobs for the entire project arrived today, here they are:
After measuring them and lining them up in the expected configuration for a single channel, two things stick out:
First, the smaller knobs with black tops are larger than i measured for. the size was there when i ordered, but i guess i mentally skipped how small the space between them should be. they need to be spaced out more to be able to fit a finger in between them without bumping the one next to it. this means i need to rethink the size a bit, although not by much. either i could cut out a couple channels which would free up a lot of room and actually shrink the whole box, or i expand the whole box by a few inches. have to think about that one.
Second, after putting them up against the frosted plexiglass, i am no longer convinced thats the right color - it just doesn't look quite right with white. it looks a lot better with a dark color, perhaps even black - but then that changes the opacity and what light can get through, which i had hoped to backlight the whole face of the controller.
then there is clear plexiglass - a cool look but i am still skittish that my novice subpar work will then be on display for all to see... but i am reconsidering it.