Referencing XAML Custom Control Names And Properties Within Code Behind?

I've created a Custom Control, and I will be placing a large number of instances of that Custom Control on my xaml page. In working with that Custom Control in the VB Code Behind, how do I do the following?

How do I reference the name of the Custom Control (in my VB code) which was clicked with the MouseLeftButtonDown event? For example, if I have 10 instances of my Custom Control in xaml, each with a different x:name (say 1-10), when a particular instance is clicked, how can I see which one was clicked? I've tried a number of things including e.OriginalSource.Name (which returns the component within the control which was clicked and not the name of the instance of the control). My Custom Control consists of numerous parts and pieces (Rectangles, Lines, Text, etc). Each of these items is a part of my layer. In VB code, once I can reference a particular Control, how can I hide or change certain parts of that control (such as hiding a Line, and changing the text). Also, I need to modify more than just the control which was clicked, so I need to be able to access properties of all of the controls, not just what was clicked. For example, if I click Control instance Test1, I also need to modify Test2, Test3, and Test5 in some way.

Here is some test code I through together as part of a Silverlight project using MS Blend 2. My control is much larger, and I need 200 - 250 instances/copies of that custom control, so I really need to know which control instance/copy was clicked.

My UserControl:

<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

[Code].....