So- when you are asking which is the most original one, it would be wise to specify which historical standard of reference you are attempting to emulate, wouldn't it.
No, it wouldn't. In fact that would be foolish. Taking that position could lead you to the wrong answer but more likely it would lead to giving up on answering the question at all.
It's a perfectly legitimate question to ask whether one reproduction
overall is "closer" to the originals
overall, even when there were 100+ originals each with differences. But you
do need to be practical about it. Puritanism will get you nowhere, because it's not a mathematically clean problem. You need to consider each feature, give it a weight for how far it deviates from the same feature on the same general kind of GT40 you're trying to build, give it a weight for being internally consistent (eg no accurate Mk II clips on accurate Mk I frames), give it a weight for how much you care about that particular feature (hidden rivet location vs. grill opening shape, for example), and continue that process until every differing feature has been evaluated for each candidate.
For example, if you look carefully at an SPF you can find "features" that never appeared on
any real GT40
ever. That's easy. I don't need to specify Pxxxx to know that
none of them used the SPF rear anti-roll bar pivot design. So if the GOX reproduces exactly one of the two or three original designs then it easily wins on that point. If it uses the Holman-Moody Mk II version on a Mk I, then it loses for that. Yes, it takes some effort and judgement to figure this out. But it's not impossible, and it's not pointless.
As for Robert Ash's efforts, yes they are laudable, no they are not relevant to the question raised in the original post. He is trying to do something even more narrow: create a snapshot of a particular machine at a particular moment in the past. To quote from his web site: "to arrive at the vehicle’s "
most significant point in time". "
If you're trying to decide which of three vendor's replica frames to buy for your HTP project, the kinds of things Ash fusses over sink into obscurity with nary a bubble, and quite rightly so. Oil pressure line sleeve crimping pattern? Yeah that's on the list somewhere, down around #1,000.