i have hull
58 from 1998
it does have such a set skrew where the shaft is connected to the gearbox
and two locking screws as well. all three need to come off.
i am going to replace mine too. but it has not leaked a drop during 4000 hours.
i am now on the third cutless bearing.
those are easy to replace:
pull off the propeller
, unscre the plastic bolt holding the cutless bearing and pull it out.
and good design