If they weigh more than a Sebring then they'll make the car feel lead-footed and horrid - Sebrings weigh 9.3kg, which is a LOT. As an example a modern Team Dynamics 15X7" rim will weigh about 6.6kg and transform the way your car feels.
Unsprung mass has a major impact in the way your car feels and rides. I'm sure they're very nice period items, but it's a heavy, old design by the sound of it.
