Returning a 301 Redirect from a Controller Action

Public Class ThingController
    Inherits System.Web.Mvc.Controller

    Function Details(ByVal id As String) As ActionResult
        Dim RedirectId As Guid
        Select Case key
            Case "legacyurlone"
                RedirectId = New Guid("c564c0c1-c365-4b0c-bc33-fd4eadf0551b")
            Case "legacyurltwo"
                RedirectId = New Guid("157fa15b-8d5d-4f04-87cc-434f7ae93dfa")
            Case Else
                RedirectId = Guid.Empty
        End Select
        If Not RedirectId = Guid.Empty Then
            Response.StatusCode = Net.HttpStatusCode.MovedPermanently
            Response.RedirectLocation = Url.RouteUrl("IdOnly", New With {.id = RedirectId})
            Return Nothing
        End If
        Dim ThingId As Guid = New Guid(id)
        Dim db As New ThingEntities
        Dim Model As Thing = ...
        Return View(Model)
    End Function

    ...

End Class