Its wonderful to see people put in this amount of time and resources in an old Datsun. I am way past my bedtime here, but i couldn't stop reading..
You are definately going the right way here, I salute you!!
I have for the last couple of years been working on a -72 myself, it always takes more time and cost more than assumed.... . I am currently installing the AZC coilovers, brakes and control arms, -then I'm gonna put in a JDM alu V8;)
I have a project thread here: http://www.evo.no/index.php?name=PNphpBB2&file=viewtopic&t=12113&postdays=0&postorder=asc&start=0
...-its in norwegian;)
Keep up the good work,