I can still remember placing several of this type on Christmas trees during the late 1960s and early 1970s. The originals have long since broken or been thrown away but I was able to acquire a very fine example from a charity shop during the 2010s, paying £3.50. In December 2023 my collection increased with an eBay purchase of five more. A little more worn, I was pleased to purchase them for the price of £15.50, delivered.
For the British 1960s market these were the 'classic' in mercury glass bells. Is it possible that some date back to the 1950s? They all have white metal caps, a working metal chime, and what looks like a double ring for hanging. The moulded bell always has an impression of the chime underneath. The height is 7cms excluding the ring, and the base diameter is 5cms.
Now I really do not know if these were actually manufactured in the UK, but I'm going to rule out an East European production at this period, but they could still be West German. And that would explain the exact metric measurements.
The metallic colours are really splendid. At least two ranges are confirmed by the variation in the white metal caps. Most are simply round, but others have a scalloped edge.
Starting off with my first acquisition, and a perfect example.

And here are my additional five. I have taken the liberty of applying a weak coat of white acrylic to the snow effect on two of the bells. The original condition had a grubby grit-like appearance which distracted the eye from the bright mercury-glass. I know collectors should refrain from repainting but this really was necessary, and the result matches better examples.

MGB