Hello sublist, recently I visited a car repair shop because my car's engine had some problems. While I was waiting a lady came in and asked for a "710 screw-top cap". Nobody knew anything about such a repair part. However, the lady affirmmed that it is a part of the car motor. She said that had lost it somehow and she would need a new one. Finally the repair shop owner asked whether the lady could make a small drawing of the part. The lady agreed, made a circle of appox. 8 cm of diameter, and wrote "710" inside. The attached photo shows the original of the "710 spare part". Best regards Otto