There is now no ship...

[Lord Gothmog]

Sauron the White

As I said, the only ones we know of for certain are Frodo and Bilbo. In your own quote it states:

"Among the tradition is handed dwon from Elanor"

This is not certainanty but simply rumour that has been given authority.

Personaly I would like to think that Sam at the least was allowed to go and see Frodo before he died. But we are not told this definately.

By my count that would mean that a majority - five out of nine - of the Fellowship went over the Sea..... Frodo, Gandalf, Legolas, Gimli, and Sam. Thats a good deal of exceptions to the rule.

If we allow that all Mortals who were Said to have travled to the West did so we have Tuor, Bilbo, Frodo, Gimli and Sam. Gandalf was a Maia and therefore entitled to go, Legolas was an Elf and similarly entitled to go. So throughout the history of Middle-earth we have a total of Five. Not that many exceptions to the rule.