Gotta make a coupla observations based on my experience. I was a Datsun dealer mechanic, no, not a technician or "tech" - a mechanic, from the early summer of 1970 until about 1980. ALL of the new Datsuns sold at the dealers where I was employed until about 1976 or so did not have undercoating from the factory and were, therefore, body color underneath. The paint applied at the factory to the bottom of the 240s, 510s, 1200, 610s, 710s, roadsters and trucks was very inconsistent from one area to another. It might be pretty OK here but thin over there. Lots of orange peel here and a bit of dirt in the paint over there. Whoa, yes, I know the trucks and roadsters had separate frames, painted a rather thin black, but the bottom sheet metal was body color. Sorry to say I undercoated lots and lots of the same cars. I seem to remember getting paid .3/hour labor for every one I did usually as the finale of the PDI (per delivery inspection) which paid additionally depending on the model.
Flash forward a number of years to my shop where I've/we've done a number of 240 restorations to ZCCA Gold Medallion standards. I hope to notch my fourth at the convention this summer. In each case I've asked the owner if he wants his restoration to reflect the way it rolled off the truck at the dealership or the contemporary standard. Before he answers me I show him the many detailed pictures I keep on file of original unmodified Zs. Remember, these pictures show details like glue running down from grommets and orange peel in enamel paint. I think you can guess the answer I always get. Carl, you're very close on your estimate of the current cost of such an undertaking. Yes, there are cheaper prices being quoted all over the place but those units will NEVER be in the running for the top prizes or pass inspection from snobs like me who have seen just about every shade of half assed restorations.
The big problem I see going forward is parts. The highest level restorations require fast disappearing goodies. Just the elementary stuff like correct spark plug wire sets, exhaust system components, battery cables, wiper blades, etc. can only be had by beating the bushes really really hard and paying a ton of money. Here's one I hear all the time - well, someone should reproduce that, if they do they'll get rich! NO, NO it doesn't happen that way. I know from my very extensive experience that reproduction, after you spend a LOT of time finding a manufacturer willing to make that widget for you, is VERY expensive. One example, for several years I've been shopping around looking for a domestic manufacturer willing and able to manufacture correct battery cables. Finally found one but the fixed costs would be about 40K for 240 positive and negative cables. Another example, 77/78 280 front and rear bumper ends, 10k for the mold and you would need 4. Chris @ S30 World, my hat is off to you and I sincerely hope you live to a healthy very old age! I know you have a TON of $ invested in your very nice tanks. PS, best of luck with your hand brake cables.
Yes, his cars are for his personal collection.
It's late and I'm getting sleepy.