I have a 1GM10 and am getting ready to inspect/replace the zinc. It appears from the manual that there is a diamond shaped packing behind the zinc plate. I ordered a replacement with the packing and received a small round washer (O-ring?) that was indicated to be the needed packing. The manual and the part received don't jive. I do know that the manual is wrong in a couple of other areas where packing, or gaskets, are concerned, so I thought I should ask the group if there is a diamond shaped paper packing/gaskett that fits between the zinc plate and engine body. If so, does anyone know the part number. My parts source and I can communicate much easier with a part number. Thanks in advance!