TUOR SON OF HUOR

[doug*platypus]

I thought it was said somewhere (maybe one of the HOME books?) that Tuor made it to Tol Eressëa, but it is never explicitly mentioned if he went to Aman. Oh, wait, yeah, it's definitely in The Shaping of Middle-Earth. Tuor and Idril sail around Aman forever, and in the Bay of Fäerie, but it is never stated that he lands in Undying Lands. I think that fate was reserved for Eärendil alone, and that Tol Eressëa is some kind of halfway house with less strict rules.

As for

But if Tuor and Idril left Mandos and dwelt as Elves in the West, how would anyone in Middle Earth know?

the tradition of The Book of Lost Tales say that one englishman named Ælfwine (and by the elves Eriol) sailed into the west and was taught all of the stories, and it is through him that they are brought back to England.