Well, I swapped out the valve. I pulled the downstream line off of it, and zero fluid was passing through. Verified after I removed it, it's plugged up.
flushed out all the fluid again, installed O'Rielly replacement. I do appear to now have rear brakes, but they aren't doing much... which I assume is pretty normal. I think the bias is supposed to be 70/30, but at least i have a little bit of help from the rears now.
I'm going to keep the core and clean it out, replace any o-rings and just have it around.