Don, although you can probably bolt up a complete 33 case to a 28, it doesn’t look as the internals are interchangeable. Especially looking at the pinion gear area. 28 on left, 33 on right. So I don’t believe a bare 33 case would have worked in my case. Again hard to tell exactly without both cases in front of you.
The same thing is true between the 25/30hp gear case of 1956 and earlier, and the 35hp gear case from 1957.
From my understanding, omc gearcases for <30hp use the short pinion, and >30hp use the long pinion.
