Neatly done Shaun, my only suggestion is that you further recess the centre base of the light holding recess so that the foil only contacts the wood around its last couple of millimeters of diameter, reducing further any heat transfer if the light is allowed to burn to an end in the foil.
But then again I have never checked it out, maybe I should do some experiments, is it better to have full contact of the foil and let the wood take care of the heat transfer or should the foil be insulated with an air gap?
Or is it me just being over cautious about wood finished with volatile products and fire in close proximity.
If using a forstener bit, I would be inclined to drill slightly smaller and clean up with a gouge and abrasive just to improve the internal finish and has been said remove the witness marks of the centre stub, but havinf said that the chance of anyone noticing or even appreciating the difference is minimal.