Yes, I agree with you that the whole matching numbers thing can be pedantic and should not be the be all and end all. As you say, what’s fundamentally important is that the car has the correct type of engine. For eg, one GTO (I think Hartmut Ibing’s car) supposedly runs a 250GTE engine (or something) and the whereabouts of the original is unknown (c.f. Jon Shirley who runs a non-original engine in his very special 166MM, but has the original matching nos engine stored so that it can be reunited with his car at any time). Re the Lusso, this guy is definitely the real deal, and has his heart set on a factory RHD, matching nos Lusso. But I do understand what you’re saying in general terms, as more people than not have bigger mouths than wallets. Not the case with this guy!
Personally, I’d have a non-matching nos car (if it came with the appropriate discount given the fact that, for better or worse, it would be considered a ‘stories’ car) if it came with the correct spec engine. That would be non-negotiable for me (though this is all hypothetical, seeing as I’ll never be in the league of buying these sorts of cars).
In some respect, this debate is a little like the Aus-delivered versus import argument… an import car can be just as good (or even better!) than an Aus-delivered car, but some people insist
on having an Aus-delivered car, and will simply NOT consider an import. And that makes buying a non-Aussie car both a positive and a negative experience, IMO. Positive because the cost to buy at first instance is likely to be cheaper when compared to an Aussie-del equivalent. However, the negative is that car may be harder to shift when it comes time to sell. Personally, I do not intend selling the cars that I buy, so I would not be perturbed by either non-matching nos (for a classic) or import (for a modern) if the car was correct spec, in excellent condition, and priced accordingly.
If I found out that my car had its engine replaced on the production line, it would be no big deal at all for me… it’s how it left the factory, after all. I’d be a bit peeved if I had to have an engine replaced under warranty, though (as someone I’ve met did with his 599), mainly because I’d be concerned that my car would be seen as a ‘stories’ car by potential future purchasers. The difference in perspective is, of course, irrational, given both situations involve an engine replacement with correct type by the factory. But for some, what happens to the car in the factory counts much less (and does not make the car a ‘stories’ car) when compared to what happens after the car leaves the factory.