A Quasimodo moment...

[Primvs Aebvtivs]

As in "The bells! The bells!" And here they are, to show what I was asked to do for a "train enthusiast"...:-
They range from about 5mm to 3 1.2 mm tall. Sized to fit between the red buffer and the bottom of the tender on a "lima" manufactured oo scale locomotive. This one is the King George V, which came to America, and had a bell fitted on it, the only British train to sport this type of bell. This is a link to the print I found on the web:
http://railwayphotoprints.co.uk/image/detail/92

[Steve Vaughan]

That's nice and seriously tiny! A tiny little train too.

[James Combs]

...Sized to fit between the red buffer and the bottom of the tender...

It's hard to tell from the photo where it might go. Any chance of a photo of it installed?

Edit: Never mind the question Steve. I saw it on the link photo of the real train.