Here's the Klon again. I wanted one with board mounted pots and for a smaller enclosure. You might be able to fit this in a 1590B with low profile jacks, but it will easily fit in a 125B. It's designed for 9mm PCB mount pots, though it might be difficult to find the dual-gang Gain pot. Look for Alpha part number RD902F-40-00. I've removed a few components that were apart of the stock bypass switching for the sake of space, so you'll want to use your true bypass method of choice with this one.