We have one of those oil filled convection heaters (made by Delonghi, ? circa 1989) that I would like to get working safely. It works fine...no oil leaks that I can see, and the switches and thermostat seem to work OK. It heats up nicely.

The problem is that the power cord is quite deteriorated, and should be replaced. It is a two-prong polarized version. The outside chassis of the heater is metal, and there is no insulated inner core between the inside wiring and the outside metal case, as I would expect to see in modern appliances with a two-prong plug.

What I would like to do is to replace the power cord with a three-prong version, and attach the ground wire to a convenient point inside the metal chassis.

Would this be a reasonable and safe thing to do? Am I correct in concluding that the outside metal chassis of the appliance should be the part that is grounded??