Farmall Cub

I'm working on a LoBoy 154 that has an IH 48" mower. It has three blades but the center one is longer than the other two- (center is 17 1/4", the outside ones are 15 7/8"). Anyone familiar with this mower and can tell me if these are the standard blades? I've only seen the 59" mowers before and all three blades were the same length, and wonder if this mower had three identical blades originally.
Charlie

The center blade is a different part number. What you have is probably right.

Thanks, Jim. Your knowledge and helpfulness are amazing.
Charlie