Hello
Actually I am not joking. People here are trying to be helpful but are getting nothing but vinegar back from you.
Perhaps your discussion should have started with the fact that you were an expert on swans, having several hundred in your collection, that these two examples were clearly not something that you had previously encountered and therefore you were wondering if they were Burtles, Tates examples without the registry mark. It would have saved the time that I and other folks here have put into searching for an answer to your question.
Sid