I don't think the question in the original post was framed correctly.
After numerous posts you decided to analyse the question.
I am not sure why you did not do that in the first place when it's obviously just a conversation starter.
The legitimacy is are they infact original with original parts and part numbers.
The 67000 is going to superior numbers to any of this old stuff but because the early stuff was uncompromised in design unlike a book shelf loudspeaker they are deemed to sound amazing if you can find one to listen to.
Why do you think the JBL statement system white papers refer back to these early systems?
I think you forgot to include a quantitative analysis comparing the number of JBL versus Tannoy in this category on eBay for example.
My own perception is that is not JBL or Tannoy but the very early Altec components that are fetching considerable returns.
Why? Because they are rare, there is a lot written about them by historians like Steve Schell and when restored by folks like OMA they are held in high esteem by the high end fratenitfy.