Inheritance in Class - vb.net

Question

Question #1: Does this look like the proper way to use inheritance in my class? I plan to add methods to the PartPnl so that both RoughPnl and FinalPnl can use together by using their objects specific data.
Question #2: Using the default values in the properties seems like the best way to get values to my object from my main form. Is that the best way to do that or is there a different approach? The main form will be open the entire time but the object will only exist long enough to do what I need, like create RoughPnl->Use a Method or two->Add Panel to form->Done
Namespace PanelThings
Public Class PartPnl
Private TrvList As TreeView
Private BasePanel As Panel
Private Label As String = Main.cboLabel.Text
Private Qty As String = Main.cboQty.Text
Private Key As String = Nothing
Private HorizontalON As Boolean = Main.chkHorizontal.Checked
Private VerticalON As Boolean = Main.chkVertical.Checked
Private ScaleToPanelON As Boolean = Main.chkScaleToPanel.Checked
Private Scale As String = Main.cboScale.Text
Private RearrangeON As Boolean = Main.chkRearrange.Checked
Public Sub New(objTree As TreeView, basePanel As Panel)
TrvList = objTree
basePanel = basePanel
End Sub
End Class
Public Class FinalPnl
Inherits PartPnl
Private FinalWidth As String = Main.cboWidth.Text
Private FinalLength As String = Main.cboLength.Text
Private FinalColor As String = Main.picFinalColor.Tag
Private LabelON As Boolean = Main.chkLabelsON.Checked
Private SizeON As Boolean = Main.chkSizeON.Checked
Private PorSKey As String = "P"
Public Sub New(objTree As TreeView, basePanel As Panel)
MyBase.New(objTree, basePanel)
End Sub
End Class
Public Class RoughPnl
Inherits FinalPnl
Private RoughWidth As String = Main.cboWidthExtra.Text
Private RoughLength As String = Main.cboLengthExtra.Text
Private RoughColor As String = Main.picRoughColor.Tag
Private RoughON As Boolean = Main.chkRoughUnderFinal.Checked
Public Sub New(objTree As TreeView, basePanel As Panel)
MyBase.New(objTree, basePanel)
End Sub
End Class
End Namespace