Drill straight up the middle, then a bit of free hand angle drilling once the dome has been formed. Led can be push in and rotated to fit in the dome. Possibly a dab of super glue to hold led in place. Taking the dimension from SL left overs. Will try and find actual size of the dome.
Only very quick first attempt this evening, been a busy day. Hope for more time tomorrow.
The led is flat, not dome shaped. Can be rotated to get best light.