Aha the plot thickens somewhat .... I struggle to understand how 4 riders / teams who surely know what happens with post race inspections have gone to the huge effort of putting bikes on the grid that aren't legal, there's absolutely no way you'd get away with it. I can decades ago remember some confusion with a definition of factory tolerance, there was some discussion that if you could buy the pistons over the counter from the bike manufacturer or they could be fitted from new then they were to be included as within a "factory tolerance".