There may be a part # on the top side, but I dont remember seeing them. A mid 70s engine would have those foldover metal straps on the RH cover, which would also have a large center mounted grommet for the VC breather. The LH side would have an oil fill cap and a PCV valve grommet. NO wire tabs on the LH side. I'm a little surprised at this question though. Nobody I know keeps these covers on their engine, since every one I've seen leak oil. I'd gladly sell you a set for two dollars plus shipping!