My concern would be were has the copper oxidized, just at the ends is ok and just needs an inch or 2 chopped off, all tgec way through would indicate the outer plastic is not tight on the inner copper, letting oxodizing air into the full length.
In that case I would change to a different brand of cable.
Current setup Thorens TD-160 Mk1 with Denon DL-110 MC Cartridge, Pioneer PD-8700 CD Player, Yamaha AX-592 Amp, Yamaha CDX-810 CD Player, Yamaha KX-480 Cassette Deck, Yamaha TX-492RDS Tuner, Monitor Audio Bronze 5 speakers, Van-Damme Cables throughout.