I have an extra 1968 emissions control manual, that needs a new home. This is part of the owners manual set that came with every US sold 912 in 1968, and has specifics and details on the emissions system. It's in good shape but not perfect (note loos like some minor liquid spillage on the top corner of the back). It is a very honest piece and pics speak for themselves.

These can be hard to find and will help you complete your set if you are missing it. $100 plus shipping pm me or email me at hoffman912@gmail.com