I'm in Los Angeles and have a carbed N42 still in my car that's a classic "ran when parked five years ago". It ran well, but has a couple broken exhaust studs and some leaks, so would be a good candidate for a freshen up.
Im not sure on value. I believe a few years ago Datsun Spirit advertised a $900 core charge, but now you have to call them to get that info. Facebook Marketplace and eBay generally show over $1k. I'm open to offers, but i think around $1k is a fair starting point if you're interested