Just changed from my L322 4.4 TDV8 to a L405 5.0 SC Overfinch, the rear exhaust boxes have the valves on them to change note but the remote control has been lost, Overfinch want £1100 for a replacement. The control box for the system is made by Red Arch but they wont supply a remote direct. Has anyone got past this problem by fitting a different control system feeding the existing valves ?