Hi Robert
The most common source is E Bay, there is a French site LeBoncoin which always lists 4 or 5 for sale if you fancy a trip to collect one. Occasionally one crops up in the Cultivator but any I have rung about have always been sold before I get the magazine. Whereabouts in the country are you ? Diesel engine options were available for the MG6 ( Drayton ) and two for the MG40 ( Drayton and Sachs ) both are single cylinder two stoke engines some Sachs were fitted with electric starts.