Postscript

I got a quote for fitting a new clapper to the bell. I decided that the cost could not be justified. I will keep the bell just as I found it and give it a tap with a wooden mallet when I wish to celebrate anything!

Then a rethink!

I managed to obtain a new ship's bell clapper and was able to fix it myself. the photo shows the bell complete with new clapper. Within a few months the colour will blend in.