G'day again Mac,
I read these posts in the wrong order but you're on a few winners here aren't you?
TDC is in principle, easy to find, at least using my dear departed daddy's method and I used it for about 15 years on my TD42. PROVIDED you have a manual.
Put it in top gear, hang onto the bull bar and give it a pull forward. Keep bouncing it as hard as you can and belt tension will crank it slowly over until you reach TDC..May cost a rooted back or something but that's what real men do. I think.
Difficulty is in seeing the tiny mark on the wheel/pulley. It's beautifully placed by Mr. Nissan behind guards/covers/bullshit etc. but with a torch you'll get it. With luck. Once you have, slap some white paint or whiteout on it as I did on my first FC Holden recently. About '57.. Means it's easy to see for the rest of your life.
Got an auto? Dunno what but if I suggest the same, never having owned an auto, I'll happily stand corrected. As for the rest, sorry mate, I'm lost.
Good luck again,
Col