Hi,
Daimler Benz have had an Approved Lubricants List (in the 50's,60's,70's it was in book form) for many decades. Their MB Spec numbers are now familar to many
As well, they always had/have a number of Lubricant Suppliers at Factory level including many smaller profile German Oil Blenders of the time. So any vehicle on any production line (the Heavy Vehicle Factory at Worth came on line during this period) at any time could have had one of a number of Approved Factory fill lubricants
As Johnny stated earlier, Castrol & Shell were supplers as were ARAL, FUCHS, BP and etc. Mobil has been a supplier to BENZ and DAIMLER and DB for over 100 years
Regards
Doug