Back to the basics,Im sure there not stock but they sure look untouched.
NEO engines have nastie combustion chambers for polution reasons and will ping at less timing than an R33 RB25.
Some shops are not aware the NEO head is different,A few weeks ago a shop removed the head of a NEO fitted to an R33 finding it looked different told the guy the head was an NA head and had to be replaced.
So yes theres lots of misinformation around.
Some strange things have happend to new cars like in the early 70s Fords GTHO Phase 4 was shelved by the government (AS were GM etc)
so ford stuck some parts on a 2 door falcon and tagged it RPO87
the rest ended up in ZF Fairlanes without the new owners ever knowing
and over the years we saw stockers with Noddy iron 9in diffs winged sumps and 4V heads with 780cfm Carbs etc so who knows what may have happened with these cars,Prolly modded very early in life by very carefull mechanics?