Nice thing . I recently sold a K80 to fund a game gun . Id had it for nearly 30 years . Best trigger pulls I’d ever used ! I’d recommend a phone call to Alan Rhone . They’ll be able to tell you the gun’s history from the serial number . They also have perhaps the best service department and machine shop of any importer , and can overhaul guns back to factory tolerances on every part . I’d also recommend ordering some spares of the little springs and balls that hold the ejectors in place ( and the punch and pins for taking the barrel hanger off if you’re an obsessive cleaner !)
Ps , just a tip , don’t snap the gun shut like you would with a Browning or Beretta , close it and then release the top lever , it’s a bit more sympathetic to the sliding top lock up !