There's definitely a point on the Bell Laps where it measures to spec. If I remember correctly, that point is just before the bar starts to bend for the drops (center-to-center).

I'm not sure about 1985, but I had a 1977 Gitane that came with bars that were something like 38cm for a 53cm frame. After riding that for a few days, the 42cm bars on my other bikes felt like driving a bus. You might want to give it some time to see how you adapt to the wider bars.

There's a nice picture showing "proper" handebar width size at this link:

http://www.jimlangley.net/crank/bikefit.html