Same Scott,
There are lots of interesting things out there, and all it takes is a bit of networking to track things down.
For example, we recently stumbled on to something very special. Cromac, another Australian Outboard Manufacturer from back in the day had produced a 4hp water-cooled unit that was maketed and sold for several years. They also developed a 10hp water-cooled unit that featured in one or two articles but never went in to production or released for sale. A few months back, we actually located the proto-type. It comprises as cast engine (completely unmachined) and raw fiberglass cowl (no gel-coat or paint). The mid-section and gearbox are also complete yet they are unpainted.
We believe the picture of the 10hp Cromac in Hunn's "The Old Outboard Book" is of the very same unit. I am yet to contact him however to confirm.
New thread and pictures on that as and when the present owner (not me unfortunately) is ready to share.
Regards,
Spiro