Mellow Hudson Mike: can you look at the attachment and tell me if this is what you describe?
And as a follow up, if I get the bell, will the bell ring every time I hit the button?
i assume that I would use a lock on, correct as I have drawn it.
Pat,
Your drawing is correct, but there is also something to remember. Bell and Whistle/Horn operate on opposite polarities. This means that, with the circuit the way you've drawn it, there's a 50/50 chance you'get Whistle/Horn when you push the new button instead of Bell.
If that happens simply reverse the connections from the button assembly to the track. Put the red wire in place of the black as it sits, and put the black wire where the red was beforehand.
Regarding how horn/whistle and bell respond, horn/whistle sounds for as long as you hold the 'Horn/Whistle' button down. The bell on the other hand begins to ring, about twice a second, when you push and release the 'Bell' button, then stops ringing the next time you push it.
Mike