I don't know about their Calls. But nobody else seems to be answering you.
I have both geese and Appleyard ducks form Holderread and am very happy with both pf them. My goose has won Grand Champion Waterfowl. Although, I think that geese are Holderrread's specialty. Still, I wouldn't hesitate to order Calls from him.
Since shipping is going to be expensive, I would email and ask for an assessment of their show quality. I would expect to receive an honest answer.
The only problem I can think of is that he doesn't ship Call ducklings and his adult birds, once they are graded and you ask for top show quality, are quite expensive. But at least you know what you are getting.
There are lots of really good Call breeders in the USA. Have you checked to see if there is one near you?