I've two Weston Mater V's that now won't move past about 2/3rds the way across the scale even in very bright sunlight. Not sure what's happened to my Euromaster, it was borrowed 20 years about ago
While in Cornwall last year I bought a pre WWII Avo meter, later sold by Ilford, and despite it's age it's still accurate, pity Ilford don't list the H&D films speeds any longer
I've two Leicameters - selenium type and they are still accurate still as well, I know that the Leitz dealer I use won't sell them as he says they are no longer trustworthy
It appears that storage conditions and perhaps how much they are used has a bearing on their longevity.