I finished the sleeves and blocked Ruddington a couple of days ago.
Here it is with the buttonhole band finished. Tucked underneath is the button band with only a couple of rows of knitting left.
For the button bands, I did my usual pick up of three stitches in every 4. This is because stitches are shorter than they are wide. As I made the cardigan a little longer than the pattern indicated there were more stitches picked up than in the instructions. I did a little math to figure out how many button holes there would be and decided upon 8 with 3 stitches bound off for each and spacing them an additional 10 stitches apart.
The sleeves are a little snug but I can fix that by reblocking them. I didn't stretch them out at all when I initially blocked them. The sleeve length is good, though.
One modification I did was knit the neck band with a needle two sizes smaller. This was recommended by Sally Melville in her 'Essential Techniques Every Knitter Should Know' class on Craftsy.com. I didn't like how the neck gaped in the larger sizes that I looked at on Ravelry. If I were to knit it again. I would add extra length from the underarm to the shoulder in the fronts and back. I would also use a smaller needle for the ribbing at the bottom of the sweater just to bring it in a bit.