The covers to the pickups were stainless steel, which is non-magnetic and therefore won't cause eddy currents, which oppose the magnetic field of a pickup, causing it to sound weaker.
The covers to the pickups were stainless steel. Stainless steel is non-magnetic. Stainless steel therefore won't cause eddy currents. Stainless steel therefore is causing it to sound weaker. Eddy currents oppose the magnetic field of a pickup.