I recall that somewhere back in one of the links from m, there was a statement that coloured glass had never been recorded from Nailsea - with Bristol (separate from Nailsea) and Stourbridge being the most likely Candidates. Newcastle also seems to get a mention as a possible source. Are there records of 'bells' originating from other countries in the earlier parts of the C19?
In the few books I have showing 'Nailsea type' bells, I'm unable to find a match with Ivo's example, so guess his is much the rarer - although the filigrana decoration and colours of pink, white and blue can be found in various glass articles from the earlier parts of the C19.
It's an interesting and attractive piece.