I was looking for information on this very subject - substitutes for north country hackles. It looks like the video linked above is no longer available? Is there another link, or does anyone know of a place to research recommended subs? I'm finding information in various places, but it's one hackle ...

I'm having a devil of a time getting more Partridge L3A/S hooks. You can find some here and there, mostly outside of the US. I contacted Dette which had been my go-to source and they said they were "no longer carrying the brand".