Dear Paul,
There is a laboratory in Rotterdam specializing in marine research.
They will examine a sample of the engine oil and tell you on basis
thereof what is the condition of the MD6 Volvo Penta.
I did one year ago, on the recommendation of the dutch ANWB .
It you are interested I could give you the address.
If I correctly remember they have several laboratories in other western
countries.
Happy sailing,
Henk Jansen
V 1682