Yes Crunch, I ought not allow my frustrations to get the better of me. My apologies.
Also thankyou for finally providing some semblance of an answer to the original question.

Classics & historics are generally expensive, can be temperamental and are usually costly to run.
It is vital that the integrity of the competition be maintained in order that those who commit the investment, time and
effort are not disadvantaged.

I understand and sympathise though with Ray's, and Graeme's, points.

In rallying we generally all play to the same safety rules and any rally car in NZ is eligible for pretty much any event. Therefore, regardless of specification, the opportunities to use a rallycar are endless.
If in racing there are cars which would, through practicality, require the leniencies of Schedule AA in order to race anywhere, it would seem curious to deny those freedoms simply on the basis of authenticity.