That's a bigger ask than you possibly realise.
Mecum's online blurbs claim that the car "...showcases originality and authenticity."
Their line with "The silver exterior..." might indicate that much of the description is cut-and-pasted from another auction listing. In any case, it is wrong. The listing claims that the car was "restored" twice, once in Japan and once in "London" (in fact, bodyshell work was performed in Wales and disassembly-reassembly in Kent).
Judge for yourself whether the work done in Japan would qualify the car as "restored", let alone remaining original and authentic:
https://www.classiczcars.com/forums/topic/68418-best-botches-bodges-and-balls-ups
It took a lot of work to reverse most of that. The car received replacement front wings/fenders, bonnet/hood, doors, both rear quarter panels, complete rear panel and floor panels. Many, many 432-specific parts were either missing or had been modified by previous owner(s) and many of the generic 1970 S30-series parts (interior diamond vinyl trim, interior plastic panels, door panels, carpets etc) were either missing or too damaged to re-use. For example, a pair of 1970 HLS30U seats had to be used in lieu of the correct 1970 PS30-D seats (therefore the 'flip forward' lever function is missing) and some of the dash gauges were re-painted to simulate their original specs.
The owner made some somewhat strange decisions regarding finishes (look at that tail lamp trim panel) and also chose to simply leave some non-original parts as-found. For example, the front brake calipers were from an R32 GT-R and the differential was an open R180 unit when the car would have left the factory with a 4.44:1 ratio 2-pinion LSD R192 unit fitted. They remained on the car when it was sold to the owner in the USA. The Mecum description claims the car has an R192 diff, but I doubt that is the case. My impression is that the owner wouldn't know the difference, but the lack of the original differential completely changes the essential character of a 432.
So, "originality and authenticity"? Not really. It's a nice enough car now (the extensive work performed on the bodyshell in the UK brought it back from the brink, I'd say) and would make a very usable and practical daily driver, but in my opinion it isn't the "exceptional investment opportunity for collectors" that Mecum claim. Yes, that's just sales patter and they all do it, but my worry is that some well-intentioned but not so well-informed buyer might end up believing he's getting Snow White when he's actually getting Joan Rivers. Due Diligence required.