S&W 4566 help

Where would I get my Smith's refurbished? (8)They are range guns and probably have 30 to 50 thousand rounds thru them and are starting to get tired. They belong to the municipality that I work for and price is an issue. ( I bet that surprised everyone?) The recoil springs, mag releases, minor repairs as well as preventative maintenace have been done and/or replaced regularly. Any and all information is welcomed. Thanks

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