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Interesting. The one on the right certainly looks stationary with cast base and large diameter flywheel (I fancy I can see fan blades on the back, but it is hard to tell). Other could be a motorcycle unit, though the silencer doesn't look right.Nice lot of spares for the money. Looks like they are on their way to Austria, bought by a someone with a taste for elegant French cars!
Just a reminder of what at least one variant of the complete unit looks like:-
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