Process and numbers sound good. Most likely the US-04 and 152 mash temp. Just brewed a double IPA with S-04 for the first time in ages; It's a little sweet. A drier result requires a lower mash temp and possibly a more attenuating yeast. US-05 has 81% attenuation where US-04 is 75%. Carbonation levels can change the whole perception of the beer; More CO2 can add some bite that might reduce the sweetness. Good luck, I'm sure you dad will love it!