True, re: the resto, but there is the fact that it is a JDM car and you ain't going to get a car like that for 10k in Japan anymore. That boat has sailed! JDM car values are not comparable to US or UK/Euro at this point if you were trying to get one from Japan, whether project or turn-key car. The variance here is that the car has had a long-term detour via the US and has been bastardised quite a bit. Makes it challenging from a value perspective. It's worth more than a US spec car, but lack of familiarity/understanding of what it is makes it maybe a harder sell compared to a UK car? Finished article would IMO be worth more due to rarity. Lots of pluses and minuses to take account of...
Also, worth noting that the missing cosmetic bits - if restoring faithfully - aren't cheap either. Fairlady Z emblems, (later spec) mesh grille, proper fender mirrors (and this car will have had the later style ones, not the ones most are familiar with) etc., all expensive. Listing needs some photos fixing, as there are a lot that aren't showing - presumably interior and engine shots. Having been in Arizona for most of its life, the interior could be a major expense due to perished plastics, etc. Nice that there's an L20 available for absolute purity - although having the L28 on board is an obvious plus from a bhp perspective!
Ugh. Might mention this to the wife - although I know the reaction is likely to be hostile and put me in the doghouse for even having brought it up...