TOPIC: Clinton air cooled???

I picked up 2 Clinton air cooled engines that are pretty cool but I know next to nothing about them other than they look like a lawn mower engine bolted to a outboard lower unit.
Ideas on age or size? I was told 3hp but not sure.
Anyone ever seen these before?

Had one awhile back. It was a 7 1/2, but a dog. Think theres still impeller though to cool the exhaust.

Check the transom clamp bracket for model/serial numbers. I believe they used Tecumseh powerheads on a generic leg.