It took a long time.
Harness is run through to the interior, and routed in the engine bay. Fuse box is reinstalled and I mounted the temp/pressure sensor up in front of the radiators for ambient pressure/temp reference.
Everything fit pretty well. I mean, it should, I measured 100x, but it's still nice when it all falls in place pretty well. I am out of large gauge ring terminals to hook up the power wiring, so I ordered some up. Next week/weekend I'll aim to get the power run, and figure out the wiring on the old chassis harness to attach to the new, and hopefully get the interior bits wired up. If all goes well, the axles will come in and I'll get the PDM programmed, ECU awake and test all my sensors/wiring fully.
Then drop the fuel tank and get it upgraded, do a little welding on the radiator, and start reassembling the car for the summer.