I sent an email to the admin of
www.OldApps.com and he sent me this page.
Old Version of BearShare are available here:
http://www.oldapps.com/forum/showthread.php?t=329
They also have even older versions from what I know but if you PM admin, he will send you the software.
He said that really old versions have some ad-ware attached to it so he will not publicly add them on the site. Hopefully this would help.