My 620 doesn't need as serious repairs as yours, and it's been off the road 5 years due to my old age and financial situation! I hear exactly what you're talking about, wanting to get her on the road sooner than years later.
Just be sure to find someone who has some familiarity with Datsun's or is an old school mechanic vs. a tech who simply swaps parts in/out. I've had some really bad work done by a couple local "professionals." One was an alignment shop who installed lower A arm bushings and a front sway bar kit. They drove the lower bushing in from the front vs. the back, and shredded the outer edge of it. And the sway bar kit was the wrong one with over length bolts. They did not compare the old ones to the new ones to ensured they matched, and installed them anyway. The nuts bottomed out on the over-length bolts and luckily they rattled as I drove it home. Otherwise I would have kept driving it and wouldn't have jacked it up to check their work. Lesson learned.
I'd like to drive the 620 to the new Powerland Event that is replacing Canby this year (the second weekend in June), but I doubt I will get it completed in time. Hopefully, I can get the dash back in my 200sx and drive it there instead. If so, I'll give you a shout and maybe we can meet up as I drive through your neck of the woods on my way up? Maybe you'll come to Powerland too?
Last, Perhaps the guy in your story whose eyes were misting up... was because he was remembering riding in the back of the police car? lol