If only adding the covers, which I measure out as 1 ounce each for t total of 3 oz. So unless they have changed the design radically in the last 2 years, comes to 3/16 pound, rather than 3/4 pound. Changing to the new design fixtures altogether might be closer to the 3/4.
The original fixtures, even when sealed against the structure still leak air around the switch operator itself. That’s what the covers prevent. These switches are apparently Renault parts - the guys who brought you “Le Car”.
The newer design is fully enclosed. It’s also easier to remove and install, thought it winds up being surface-mounted, as it has different dimensions. It is far more expensive.