There were some hard to reach nuts and bolts corroded stuck. I started to distress. Then I sliced those suckers off with my Dremel tool.
There were leaks all over when testing. But then I brought back my dialysis plumbing skillz, ID'd the culprits and wrenched the crap out of them. (Good thing too, because my next troubleshooting step while hooking up in the ICU was to say "Screw it" and make a fancy drip catcher out of an eye-shield mask to guide the water down a drain. That's only a good a few hours of treatment while I monitor for flooding.)