Way to go Nettie! The Zone System is a great book - I used it to get up to speed myself. You'll find eventually though that it doesn't cover everything. A simple example is adjustment layers - not mentioned anywhere - but a crucial element in processing IMO so you can backtrack and refine.
Your 1977 is looking good! I think you just need to do longer subs next time if noise will allow. You've also black clipped the blue channel somewhat I think (?)
Keep 'em coming!
Cheers, Marcus