I am looking into buying a boat and I have my eye on a 1980 Sea Swirl Cuddy Cabin 19' Polaris. The owner says everything is good except it has a leaking seal in the upper gearbox(of the outdrive) that leaks into the water intake. He says the seal kit is $50 but a pain to get to. Does anyone have any experience working on one of these? How difficult would it be for an amateur DIY mechanic, or how much for a pro to repair it? Thanks!