Looks like this prop has seen lots of use...I can see some 'bite' marks where the propeller has hit something. That's not damage though, in modern machine circles that's provenance.
BTW, good pix.
I did not know who invented the boat prop, until reading your thread, although I do know that the outboard boat engine was invented by Ole Evinrude, an American, born in Norway. I probably know this, because we have an Evinrude twin cylinder.
Good small engine though, pops away nicely as it pushes our large freighter canoe through Canadian Shield waters. I guess Ole knew something.