Chieftain NR Low D Question

Earlier this week someone posted a link showing Phil Hardy of Kerry Whistles playing a number of high D’s, after watching that on Youtube I followed some of the other Chieftain whistles links including this one:

https://www.youtube.com/watch?v=bKQTO_qosVc

I’m a touch surprised by this, around the 11 seconds mark Phil clearly states that the Chieftain NR low D was only available in tuneable, yet I have a fixed non tuneable NR low D dated 2004.

Can anyone shed light on this please?

Maybe he stopped making the fixed NR low D’s after a time. I have a very early model NR low D that’s also not tunable.

In another video Phil says that, early on, they made 200 fixed NRs.
https://www.youtube.com/watch?v=VJ2P2gW8WZI

So apparently they made quite a few.
I have two fixed ones that I think are NRs. Not sure though. They might be the OS.
They are great whistles!
Judging by the photos on the Kerry site they are OS, but according to some players they are NRs.

Thanks for the reply’s, that video is very interesting.