Painted Lady is still registered and widely available online I believe - brick & mortar retail may be a different story altogether.
Sorry @ancellsfarmer I don't know anything about the origin of Wey, but I hope others may be able to elucidate more.
It is claimed to have self-setting ability which makes me suspect it could be one of those new French bean crosses by Tozer Seeds, which is also in the vicinity of the river.
According to the plant variety database it was on the Netherlands national list from 2007 to 2017.