It looks like they have lots of tail feathers, more than a normal pigeon.
Maybe they are fantail X a crested fancy breed?
Danzig high fliers have long pointed heads and beaks and long flight feathers that reach nearly to the tail end. Also 'pearl coloured eyes'. and in my opinion these don't look quite like that.. these have bull eyes and short beaks, with short and round heads.
Their head shape is very much like my Dutch Capuchines. And their body shape is rather like a fantail pigeon, with the big chest and curved back neck.
My money is on fantail X Capuchin. Just a guess really though! I am very jealous of them.. very pretty looking birds.