Well I must confess I've never had an R4 from new and don't really know what was in their toolkit or even if they had one.
But the Dauphine, R10 and R12 all came with a tool roll with a couple of spanners, screwdrivers and a spark plug socket as pictured.
I just assumed Renault would have done the same with the R4.
That socket is just the best thing for getting into the plugs on a Ventoux engine.