1949 would have Dumbells. The switch was made in the early 50's with the introduction of GS, to the best of my knowledge.
>From: "Aldo Ross" <swampmtn@siscom.net>
>To: <Classicrendezvous@bikelist.org>
>Subject: [CR]early Campy qr question
>Date: Tue, 2 Jan 2001 16:55:44 -0500
>
>When did Campagnolo switch from the dumbbell bolts to the D-ring on their
>hub quick release nuts? In other words, would the 1949 Wilier have
>dumbbells or D-rings?
>
>Aldo Ross