'88 190E parking brake tensioner

My son has brought home an '88 190E, not a terrible car for NY salt, but the E-brake assembly is not working, I haven't been under it a lot, but it seems that the cable adjuster/tensioner assembly has self destructed. Any ideas on a source? I searched eBay but without knowing the Benzophile name for it, found nothing....are these available aftermarket, and what sort of price does he need to expect in order to get it inspected?