We have Promethean ActivBoard connected to a short throw projector [The board is on a wall-mounted hoist allowing it to rise and fall]

The board has been damaged and does not work. When trying to source a replacement we can only find the newer type [ActivBoard 300 Pro or similar] which will not fit on the wall mounted hoist. This means that a new board will require a complete re-work of IWB unless we can source another ActivBoard 78. Does anyone have one they are getting rid of this Summer?