Changing Silverlight view - silverlight

Question

I am trying to create a extension from an existing view where I have a list of text controls and in the new project I would like to use this control and change one of these text boxes to a radio button.
Using MVVM makes it easy to use the same code without having duplicated code, but for the XAML view I find no good way to do this change without creating a copy.
Example:
Core project with the main user control
<UserControl x:Class="SilverlightApplication4.MainPage" Name="test"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="400">
<Grid x:Name="LayoutRoot" Background="White">
<StackPanel>
<TextBlock>
asdfasdf
this is a test
</TextBlock>
<Button Height="120" Name="asdf" Content="This is a Button">
</Button>
</StackPanel>
</Grid>
</UserControl>
Now I have a second project where I want to change the TextBlock to something else.
<UserControl x:Class="SilverlightApplication1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"
xmlns:core="clr-namespace:SilverlightApplication4;assembly=SilverlightApplication4" d:DesignHeight="300" d:DesignWidth="400">
<core:MainPage>
<!-- how do i change the type of child elements?-->
</core:MainPage>
</UserControl>

Answer 1

Solution will be to use a ContentControl and bind it to a ViewModel through Caliburn.Micro.
I added an example and code to my other question (below the XAML section): Project structure for EF/Silverlight application