I'm looking for a used engine cover/cowling for my 2004 Honda B50A. I always assumed that B50A engine covers were identical, but just to make sure, on further investigation at Boats.net, it shows a 2004 B50A engine cover, item 31 part no 63100-ZW4-H01ZA at $380.79. Whereas the 2003 B50A engine cover item 36 shows the part no as 63100-ZV5-010ZA at $676.97. Different part nos and a considerable difference in price. What actually is the physical difference between them, does anybody know? I don't want to end up with the wrong one.