Interesting find Giblet !!
Remember the times when Ferrari (for years) was displaying Agip on their cars.
I´m well aware, that a technical partnership and a sponsorship deal, are two different things.
See the current Mercedes GP Petronas/Mobil1 (Exxon) situation, or Peugeots Total sponsorship while using Shell race diesel in LeMans.
Similar things happen, while I was working with Toyota in the WRC.
For the first year(s) we had Repsol sponsoring (Carlos Sainz) but still used Duckhams engine oil, until Repsol was able to provide the oil(s) and lubricants we needed, which later on was the case.