the fised lens Contessa family are very interesting and funny cameras.
I've found that light meters work in most of the ones I've gotten.
Selenium meteres are not killed as much by age/light as they are by humidity/corrosion.
If the meter responds to light when it gets to your hands you maybe able to adjust the variable resistor in the metering system, also when you lift the top section check and see if the contacts are corroded or loose, and clean or resolder.