crossover rebuild/retoration

I am looking for some help in locating a reputable shop to upgrade the original crossovers on my vintage Yamaha NS 1000M speakers. I am the original owner and bought them in 1978. They play just fine but thy have not been used for years and I'm thinking the crossovers can be improved on and maybe better internal wire? I don't know what they used back then. Also modern binding posts. Any help would be greatly appreciated. Thanks, Allen(aka Mizike)