Can I undo 301 redirects to purchase site

[atomiconline]

A website I am thinking of buying has 301 redirected all pages on his site to one page that explains the site is closing down. If I tell him to change the 301 to 302s will I be able to recover the old pages on the site and keep the authority, rankings and link power of the old pages and not the "Closing page"? Is all i have to do is undo the 301 redirects and everything will go back to how the site was before the 301s were in place? Or will I lose all the link power on individual pages because they already transferred to the "Closing page"?

Thanks!

[MattRoney]

Do the original pages still exist in their original forms? Has adding the 301s been the only change?

[MickEdwards]

Yes, that is the key - what has happened to the pages on the server?  You would hope that they still exist and you can revert.  If the site is in tact you can just remove any 301 or 302 redirects and restore.  It may be that Google has removed the URLs from the index but these would be crawled again once the redirects are sorted.