One advantage of the $10 ignition switch that was standard equipment on my VS is that the designers have already minimized the mass of the key. No further lightening is required - or even prudent.
And the pot metal in the switch body is also the lightest alloy obtainable.
The key shape is correct for mailboxes and piggy banks of the period.
And in a master stroke, they extended this 'less is more' design philosophy to the switch contacts, too.
