Progress! Again.
I strapped the fan onto the front of the rad, plumbed the rad, found a better arrangement for the oil cooler and PS cooler, and realized it opened up a nice space in around the radiators for the oil accumulator!
This means I'll be replacing the hood latch support hoop with the brackets and braces I'm going to build for the radiators, along with a bracket for the oil cooler thermostat. I am decided: the accumulator is getting a remote-switched solenoid valve so that I can put a fuckoff-bright LED on the switch that will warn me if the ignition is on but the accumulator valve is closed.
Behold, a fully plumbed water and oil system!