Worry not Mark. The issue of failing rocker cover gaskets was confined to the earlier, two valve, motors.
Why, after decades of no problems at all and seemingly no change to the mating area design between head and rocker cover, the gaskets started getting squeezed out and failing I have no idea? It only seemed to start with the CARC bikes and as a rule tends to occur more often on models with the 'Rounder' profile rocker covers, (Breva, Bellagio, Norge.) although as proven by Roy's bike it's not exclusive to them.
The answer though is very simple. Just get Valpolini gaskets. These won't rip or get squeezed out and last pretty much forever. End of problem.