Matty F FIRST wrote:

A number of bells have been cast in brass. The castings are somewhat
rough, and the outside needs polishing.

Then LATER wrote:

They are not musical instruments - they just make a ding ding noise
and llook shiny.
Any pitch will do.It's better if they all make different noises, then
the driver will know which bell is which!
Here's one that somebody else polished:
http://i45.tinypic.com/2h4evxc.jpg

Well flippin' 'eck!! Am I the only one who thought Matty was talking
about Bells, as in Church Bells?!?

You're also in NZ Matty (by the look of it), so "local" uk.d-i-y advice
ain't a lot of use to you!

Personally -- seeing the "here's one we did earlier" -- I'd just get the
Brasso out, along with the old tooth brushes.

J.