I have to disagree with your dating of the writings of Isaiah. Literary scholarship shows that authorship was by more than one person and that different sections were written hundreds of years apart.
Here is a list from before this century
http://www.biblicalresources.info/...saiah/mulauthorshp.html
As for Jeremiah we have some historical anachronistic issues with him and his prophecies. Tim Callahan in his book
'Secret Origins of the Bible" states it quite well on page 336.
"The historical error is that the Babylonian Captivity lasted only 49 years (587 to 538) as opposed to 70. Jeremiahs''s prediction of a 70-year desolation (jer.25:11, 12) was probably a way of saying a long time (a sabbath of decades) or a lifetime. It is interpreted as literally 70 years in 2 Chr.36:20,21. The Book of Chronicles is thought to have been written in the time of Ezra and Nehemiah, ca 450. Daniel's acceptance of literal 70 years is yet another indication that the author was not familiar with the time period in which he has placed his hero. More important, however, is the anachronistic use of the Book of Jeremiah, which in Dan.9:2 is already part of the word of God. Yet Daniel was supposed to have lived during the Exile. Hence his lifespan would have overlapped that of Jeremiah. Thus, Jeremiah's word would not have been made part of the canon"
This little snippet shows how difficult it can be to date or even chronologically arrange books of the bible. In order for you to claim these to be prophecies you must provide some proof to the actual dating of these books and prophecies. Just because tradition gives a date does not make it true.