Why should I be surprised? Can't I read a wiring diagram? Can't I follow a blue wire with a white stripe?
I was still surprised. I've connected enough electrical stuff and had smoke puff out just before the flash that there's a reservoir of surprise left.
The flashers took a little more work to get clicking, and I don't know whether the horn doesn't work, or my non-button test of it was not right, but the starter does crank. The next steps will be to get the undercar setup complete - the fuel and brake lines, the battery cable, and finish tying down the exhaust system. Then, a couple of quarts of gas, and it should start. It did once, long ago in 1999. It should again.