SQL 2005 (64-bit) Linked Server to Oracle 7.3

Hello -

    I am trying to set up a linked server from 64-bit SQL server to a Oracle 7.3 (  a client platform ) using ODAC 10.2 (64-bit) OLE DB provider. The linked server has been set up, but connections fail with the error attached as a code snippet below.

   Given that we -
   a) want to stay on the 64-bit platform on the SQL Server side
   b) cannot persuade the destination end to upgrade to a later version of Oracle
   c) there are no 64-bit client tools (older than 9i) that would let us connect to a 7.3 server.

   Is there a way to make the linked server work?

Previously posted on the SQL Server zone without success :
http://www.experts-exchange.com/Microsoft/Development/MS-SQL-Server/Q_23168116.html
( I'll award points in both threads for acceptable solutions )

1:
2:
3:

OLE DB provider "OraOLEDB.Oracle" for linked server "legacy_oracle" returned message "ORA-03134: Connections to this server version are no longer supported.".
Msg 7303, Level 16, State 1, Line 1
Cannot initialize the data source object of OLE DB provider "OraOLEDB.Oracle" for linked server "legacy_oracle".