You can get 30% off list on Filson from a US-based supplier with the same name as a bird:icon_smile_big:. This makes it around $175...if it's the one you want, it's worth stretching, especially as it looks to me like a lifetime piece.
If not, I think John Partridge is good and you can sometimes pick them up on STP (I think it's the Zetland). Edit - here's another option
Happy hunting!