For Fuzz Friday, here's the original Fuzz War from Death by Audio. It's essentially 5 gain stages going into a Big Muff-esque tone stack, into a clipping stage and a final gain stage. Here's the schematic for reference. Original models have the Fuzz control as a trimmer internally, but I've laid that out as an external control for more versatility. Pots can be board mounted using right angle PCB mount pots and it should fit in a 1590B (though personally I'd put it in a 125B).