Re: out island cutlas bearing (how to remove)
My 1974 OI 28 had one or two set screws. Brass (to better match the outer sleeve of the bearing), placed laterally. Pan-head screws, so the heads were on the surface of the glass. I don't recall whether there was a threaded insert embedded in the fiberglass.
At any rate, if you've removed all paint and the can't find a screw, it may simply not be there (backed out & lost, or never installed). Getting the bearing itself out required a slide hammer. I made one myself out of 3/8" threaded rod, some carefully sized washers & nuts, and a footlong piece of 1/2" galvanized pipe to which I welded a 3- or 4-pound blacksmith's hammer.
It made a lot more racket--and took a lot more force--than I liked.