found it
"to maintain the natural preservation, the engine . . .is to be operated each 5 days.. . in case of longer than 15 days should be preserved . . . inject 40 grams of oil warmed to 50 degrees C into each cylinder and turn crankshaft . . return plugs."
mmm . . . I wonder what type of oil, normal engine oil I assume, then how does one get it out before start? Or doesn't it matter? Wont it just flow down to the bottom of the cylinder leaving the top exposed?
And the valves, I don't want engine oil to burn on the seats.
I'm thinking to search for a specialist vapour oil product - the manual was written before these products were available.