The nice thing about a moldy, rat infested, 45 year old racecar is that there's never any question about whether this or that part has to be pulled off and stripped down. Everything is dubious in some way, or at least moldy.
I've been slacking on posts here, so here's a month's worth of vehicular archaeology.

What's this about?
Probably nothing, moving on.
The brake fluid reservoir had a busted cap and was full of water.

Looks worse than it was, it's moving freely now. Maybe we got lucky.

The two motors got combined into one.

If the heater fan wasn't seized I would have gotten a face full of spores as soon as I turned it on.
I'm getting a lot of use out of my respirator on this project.
Removing the dash of a Mk1 Fiesta feels like an exercise that should be part of automotive engineering school, because it only takes 5 minutes. Then removing the heater box, cluster, steering column, pedal box, and wire harness only takes another 15.
You don't need a shop manual for this thing because the removal procedure for every part is the same, unscrew two bolts, remove part.
The whole heater box is held together with two spring clips.


Good as new. I'll probably keep the heater core bypassed for the race. Those plastic fittings do not inspire confidence, especially if they're made out of the same stuff as the brake fluid reservoir.
Next up was wiring.
The harness was simple enough to beep out with a continuity tester. I'm still a little confused about the purpose of the push-pull direction of the blinker stalk, since the high beams are on the right stalk. Anyway...
The plan here is to stuff the branches of the harness related to the original ignition system into a coffee can or something and forget they exist. Then, terminate the wires for the cluster in the glove box where the ECU is with all the rest of the electrical hackery.

The e-stop solenoid and battery will be in the trunk.

I scavenged a quality e-stop and a bunch of nice switches from a discarded control panel.
The night we picked this thing up I took about 300 lbs of wet parts out of the trunk and heaped them into a storage shed to dry out. I'm still not sure what all is in that heap, but for the most part it contains parts for this car. I can usually dig through it and find one or more of what I'm looking for.
When I went digging for the radiator and cooling fan, I found this.

That explains the little rubber VAG part under the grille.
We'd like to complete the race, so the VW parts have to go.
Went back to the parts heap, and it provided the OEM part.

Just a little busted.
Both fan motors were seized up, so we fixed the original.

By going back to the original radiator fan, the car regains +1 orangeness.
The brushes were in great shape, but the bearings were crusted.
Freed up the bearings, but I'll need to run it over night before the race to know for sure if they're happy.

New connector, for what it's worth.