Engine?

That's right! Rear brakepipe from 2CV used as a hydraulic pipe for the front suspension. Same connectors and pipe diameter.

Not the engine, luckily

I'm sure a similar tool I made for the XM can be made to be used with the 2CV engine.

I made quite similar tool for my "British humour". Forgot to change the seals when changed the head. Took three days to change them to installed head, and less than hour to head on bench...

Thanks for the advice.
Think for the time being I'll leave as is.
As I say, oil consumption is minimal, plugs are clean and the lump runs perfectly.
As I am not able to cobble together the necessary compressor, I shall wait and see if somebody has made the right tool.

Thanks again.