Hello Bill R., Jeff, Eric, Bill K.,
A mechanic came by. Without my prompting, he did the test of loosening the fuel lines to each cylinder one by one. With each one, the engine roughened up, then straightened up when tightened again.
He removed the "air filter" (which was oily), cleaned it, and after a few seconds, it was oily again.
He ran the engine fast (in idle) and slow. He agreed that there is too much smoke and oil in the exhaust. He removed the oil cap and put his hand on it. Did the same with the oil dipstick.
Unfortunately he has zero English and my French is less than passable. I got that he can't take me on, and that he thinks a technical test of compression/pression of something is necessary. I think he was referring to the fuel pump, but he may have meant the injectors or, less likely, the cylinders.
I'm also pretty sure he said this is not a minor project.
Anyway, they'll call me later with a translation.
By the way, the engine timing was last checked 125 hours ago. Valve clearance last checked 88 hours ago. The cylinder head valves are 125 hours new. The shaft brake was replaced by Amel two years ago and clears the disc cleanly. The propeller was thoroughly cleaned by a diver 88 hours ago (43 days). A diver is coming tomorrow. The oil on the ZF Hurth was twice flushed 383 hours ago (13 months) and it is crystal clear/no level change. The oil on the C-Drive is 289 hours old and crystal clear/no level change.
I'll have someone check the transmission oil cooler. It has not been serviced. The turbo was removed, thoroughly cleaned, painted (twice) and reinstalled 125 hours ago but I am not sure it was "tested" or what the performance tests are.
Thank you all for your input. If this guy won't take me, I'll probably be looking for a well respected Yanmar outfit in France or Spain and probably have to park ourselves there for two or three weeks while they drain the oil, I mean, our bank account.
Any other thoughts or recommendations, please do post. Thanks again.