Add Feature to Javascript Timeline Script

I want to take an existing script that creates timelines from data and add functionality to it. What I need is to be able to set the height of the timeline to something specific so it doesn't change (this is already a feature) and when the events start to stack and go up beyond the viewable area, add an icon with a plus symbol that would represent that there are additional items above with a number next to the plus symbol representing how many are not showing. Oh...so don't let the items above the viewable area show (have them hidden...or rather...the stick and ball under them since you couldn't see the label anyway). When the user clicks on the plus icon label it will need to zoom in on the timeline to be able to show the hidden items comfortably on the viewable area. The script is found here: [login to view URL] See sample image attached.