Antony G. (asker) Feb 26, 2018:

Thank you Tony, I'll take your advice.

Tony M Feb 25, 2018:

Peanut I don't know anything about hydraulic couplings, but an unsheleld peanut has a fainlty 'figure-of-8' shape — sort of oval, with slightly a constricted 'waist' in the middle. I should imagine this has something to do with the shape of the couplings, perhaps some kind of nipple?
If you look at manufacturers' sites to find what the type looks like, you should be able to then find what they are called by French manufacturers.
If the worst comes to the worst, phone some on Monday morning.
OK, if you Google "hydraulic peanut coupling", you will see plenty of examples, which correspond roughly to what I was describing above; you may find some of the EN manufacturers' catalogues havea FR translation that might put you on the right track, or if not, look for similar products from FR suppliers.