You are absolutely correct. Not many folk understand the adjustment cap/nut feature on the early Record OR brakes (later versions were essentially the Icarus design with its conventional pivot). The cap very precisely screws up against the brake arm providing a stable support - this allows just the thin arm to pivot on its bearing, rather than requiring a wide bushing to stabilise it like all other brakes.
It’s a clever, unique system as you say, and reduces friction in the pivot by supporting the arm front and rear.
It’s a clever, unique system as you say, and reduces friction in the pivot by supporting the arm front and rear.