It will be a rare find as nearly all are returned for core credit on
change-out. Unless you are an expert weldor & machinist with time to
dub with it you need a new (rebuilt) alternator unless you get very
lucky. Rebuilding the alternator yourself with a new housing and for
reliable life is problematic, too, unless you are skilled at this work.
You also need to find & correct the reason it broke, unless it was
from playing caveman with it at belt time. Verify bracket condition &
sheave alignment or excess vibration problems, etc. An
starter/alternator rebuild shop could identify what the alternator
really is, as is isn't made by OMC or Volvo, but boat alternators are
marinized versions different from those used in tractors & vehicles.