No idea . Model # serial # year of manufacture. Where did it come from ? Any chance of going throuh the original supplier for replacement parts? Look at it this way , you ain't got the only one ever made LOL theres some parts somewhere.
When faced with a situation like this , I always go to the manufacturer for parts . They may not deal directly with you but will always put you in touch with someone who can help.
I believe you need to know what hydraulic ram you have to know the seal kit. Sea star had a model number on all their units and they are easy to find. Call them direct or go to a local marina that carries their parts and they will order it for you with no problem.