So I'm in the final process of building an all tube amp for my school engineering project (pics will be coming fear not) But I bought pots with a 8mm smooth bushing. I can't seem to find knows that fit anywhere, and I ordered some Marshall knobs but they fit 6mm not 8. Can anyone help me out? Dome or bell shaped knobs are preferable, as are set screws, and in gold or black, the chassis of the amp is gold, and it has a brown western tolex with beige fender tweed. Any help would be awesome!!