The short part number (only 4-digits) suggests that the switch, cable and end connector is a custom assembly - made by Marquardt for your bike's manufacturer. If that is the case, then the switch is unlikely to be available on its own, and a new replacement assembly might only be available through the bike manufacturer's dealer network.
Failing that, it's either obtain a used assembly (e.g. from a scrap yard or eBay), repair the one you have or modify some alternative switch to fit your bike.