Original part number 277594, superseded to 204100. Roller bearing surfaces need to be very good. The lower crankshaft bearing surface runs in a plain bearing so not necessarily as good. The crankshaft has cast in casting number 203711. I think this is a one year only crankshaft. Same crankshaft is in 1956 Evinrude 15.
I live in Durham, Maine. Tel two oh 7 three 5 three ate wun ate 8
Thank you for looking.