Trying to repair a Roland DigitalPiano hp-4500s. Three conductive contact rubbers are torn and need to be replaced. Tried to find the roland part number from the service notes which are combined with the hp 2000 and 3000. And guess what wrong drawing of key/tangent. Thus cannot find the partnumber. On the net (aliexpress and ebay) i can find patches which are look alikes and fit into younger models. But no provider gives measurement specs, so i am not able to verify if they fit. Anybody in here who knows which one fits or how i should go forward?