My answer is simple. You require a plastic food container, my local Indian takeaway provided a suitable one, a circle cutter and ruler.

Measure the diameter of the bottle, set the circle cutter to half this size and cut. My effort was a bit ham fisted but resulted in a nice, tight fit suitable for all bottles of 38mm diameter. Cut the hole in the base not the lid as you can use this without the lid fitted

Lesson learnt. Other glues and boxes are available
