I have a Row Crop  Oliver 66 that has 3 point on it.   I don't think the 66 came out with 3 point but maybe the later supers and 660s did.    How do I know if the 3 point is Oliver or an add on?    I know the cylinder is an Oliver one.  I am looking for numbers stamped on it.   Will the 3 point fit on the 77 or 88?   thanks and Merry Christmas all.