After getting all three axes to work, I decided making an extruder from ground-up would be an exercise in frustration and likely get me to never finish. So I purchased a Wade's Extruder - and realized I still needed a stepper motor driver for it.
While I have some stepper motor driver boards, they are of version 2.3, which are surface-mount and not something I've ever tried before. I've been scared off a little by that, and by figuring out which exact components to get - the lists from the original description are gone (this is why you don't just link to some random other place, but copy it in). So it's slow going at the moment, but then, it's a nice summer right now.
I should also make some proper tags for the opto-endstops with better fastening. The cardboard ones I made got all broken by me fiddling around with other stuff. Not good enough.