Some news to close this issue.
I eventually acquired a genuine Ford thermostat/calorstat (number 815F 8575 AAA) from the french 271x Ford dealer, namely Fornaut, in Le Pré Saint Gervais.
Cost for it was around 25€ plus extra 2,7€ for paper gasket, VAT incl.
They confirmed the exact location of the thermostat at the top left front of the engine seen from the inverter.
The recommended a “start to open at 71 °C” version for a marine engine and they recommended tIat I cut and remove the somewhat movable restriction (copper part, at 3 hours on the attached picture) in order to ease cooling flow.
Their courtesy was to supply me with a pdf version of the 271x 1975 service manual, in french, which may prove unvaluable while undertaking services. Please drop me a note if you like a copy of it. Richard, do you thing it has it’s place in the association repository ?
