Quote: SOP in this case is Standard of Perfection.....APA is American Poultry Association.
So you've probably got some good birds from what looks to be a serious breeder.
Have you checked out the Welsummer Club of North America?
Rather young/new club, but you could get some good feedback there, once your birds are older.
They have a Facebook group that has some participants from Europe. https://www.facebook.com/groups/welsummerclubofnorthamerica/