We own the boat (1988) just since april 2005 and are not to familiarwith some aspects:The coupling is quite rusty and we think it should be replaced alsobecause the shaftseal needs to be replaced.Since boat is not nearby and we are not able to measure the shaft etccQuestions are:- does someone knows the exact diameter of the shaft ?- any tips for a new coupling ? brand, type ?- any tips for replacing the seal ?I look forward to you reply