This is a very rare item... It was produced for only six months and was relatively expensive.
The tank, pipes and caps are all plastic, now 60 year old plastic. If you ever see one of these DO NOT flex the pipes to open the caps... they WILL break.
I bought lots of French military Dinkys on a camping tour of France in 1965 (in a Hillman Imp). I didn't buy one of these as I couldn't afford it even then.
It took me many years to find a really good example, this came from a dealer in the Channel Islands and was old shop stock. It has been safely behind glass ever since
These are quite often faked up to look good but are almost always 'wrong 'uns'. Currently fetching over £400