Good job! I replaced my digitizer on mine a while ago and realized that my buttons didn't all light up either. The replacement digitizers don't come with the pieces required to carry the light from the diode to the button. If you find your old digitizer, you can peel off the plastic pieces on the back of each button and stick them onto the new one.
Do I need to remove the digitizer from the new one to apply those pieces? If so, I don't think it's worth the risk of another "non-working" handset...