Eriol's Backstory

I began the second volume of The History of Middle-earth today. The first Tale from the book is extremely long and I did not have time to re-read it and do it justice. However, the first few pages caught my attention. We pick up with Eriol residing in Tol Eressëa with the Elves. He had been there for some months and winter was come. A lass, Vëannë begged Eriol to tell stories; a sharp role reversal for him. And he proceeded to tell about his journeys. We learn the following about him (from two versions of the story):

• He remembered a tall tower as a boy
• His father whetted his appetite for the seas as he ad descended from coastal folk
• His boyhood town was sieged and his mother and father were both killed
• In one version Eriol escaped and in another he became a slave
• He had participated in battle in his day but did not wish to tell much of it
• Eriol told of his sea-wanderings and in each he shipwrecked and met an old mysterious sailor on an island who told Eriol of strange tidings in the Western seas
• This set Eriol's heart toward the West until he finally, by the grace of the Valar, reached Tol Eressëa.

I found this background interesting, albeit brief. Their are snippets of Eriol and the characters he meets that are colorful but integrating them into published works would be a daunting task indeed. What I found most interesting about Eriol's backstory came at the end of the second version when a lad named Ausir spoke up: "'For knowest thou not, O Eriol, that that ancient mariner beside the lonely sea was none other than Ulmo's self, who appeareth not seldom thus to those voyagers whom he loves..." (p. 7, The Book of Lost Tales - Volume II). Could Eriol have indeed encountered one of the great Valar? If not, I do not know how he would have found Tol Eressëa.