After I had the centerboard cut at a local foundry I soon discovered that not all Rebel centerboards are the same. My Rebel # 336 is probably the oldest Rebel still in service. (I'm going to get mail contradicting this, I know. But, I'll make the statement).I had to cut it again to the shape below.My point is, if you're going to get a new centerboard, measure the old one before making your purchase. To be even more accurate, while the boat is on land and turned over or lifted up, measure the inside of the centerboard housing..
Centerboard as re-cut to fit
Design of standard centerboard
Editor's note: I have seen boats with lower numbers than Larry's. His boat is about 45 years old , thus some thing may not be the same as a boat 40 years old. The first Rebel's had wood deck's as an example. His point should be taken in that if you are replacing the centerboard of a boat with a number below 500 it may not be the size of the class spec's