It probably came with about a 9 x 10-1/2 aluminum 3 blade, or thereabouts. Check to see if they have them here at iboats. Next time, use a stainless steel cotter pin so that doesn't happen again.
The motor started life with a 9-1/4 X 11 part #377636 3 blade aluminum prop according to the factory parts manual. They also listed an optional prop, part # 592959.
