I do hope I’m not giving too much feedback here, but… 
I’m trying to add the cuffs now, but after attaching them I just saw that I’m expected to let the seam allowance at the sides stick out past the side of the sleeve?
That is, this image seems to suggest that:
Here’s what I did instead:
If it is, indeed, expected of the sewer to let the seam allowances stick out at the sides, maybe that should also be said rather than only shown in the illustration. (But, of course, if experienced sewers would just know that, and such information would be superfluous, feel free to leave it out!)