Okay, after comparing the KC02 valve and the NPAS, many things were different.
Although, there were only 1 diameter that would need some change to make it at least feat, if not work.
So, this morning, I had it machined on a lathe (is that the correct way to say it?).
It was a bit risky because it didn't leave much matter on the NPAS and would weaken it, but it survived.
And this afternoon, I fitted it in place of the stock valve.
Firing test... Okay
Adjusting test... It can adjust the output power. It's probably not the definitive product as I may tweak/test some more but for the time