Done and done (per DieselGiant's illustrated manual), all looked good (no more than 0.9 ohms resistance on the plug wires and 12v on the relay and the powered plug lines test).

I noticed this morning that I cranked the motor for like 15s, then stop, then cranked again for like 10s, after which the motor started very strong (no sputtering or anything). There doesn't seem to be any leaking under the car, perhaps there's an air leak elsewhere? Is there any fluorescent dye that's usable for this car that would help find out where any pinholes or loose fittings in the system are?

(to update: the thermometer registered 27 degrees this AM, car parked uphill,and the start was the same as always: glow for 20s, crank for 10s, then crank again and she starts right up, maybe 5s of roughness then a smooth idle.)