[Schulisco]

Here's a users manual for the '72 911S in German:
http://content.us.porsche-clubs.porsche.com/PorscheClubs/klassieke-porsche-911-en-912-club/files/BetriebsanleitungTyp911S1972_V2_Optimized.pdf
It says that oil level has to measured at operating temp of at least 80°C as defined as warmed up engine. And it tells that the oil temperature must not be higher than 130°C. Otherwise slow down, check the oil level and go to a workshop to clarify the issue. Normal operating temp on an aircooled 911 is 80-100°C depending on ambient temperatures and driving conditions. Higher temperatures are not common on normal cruising.
Oil temp varies depending on driving conditions. On idle at hot summer days in heavy traffic it might climb up to 100°C and
even a bit higher but it should fell to normal temps immediately when driving again. If it drops less than 80°C on a non winter day check the oil thermostat in the rear right wheel housing.

Thomas