order: AE-1000035-5V PS3/2 board w\ 5 volt adapter board.
IC-0000026 Hardware mounting kit: and if 50mm speaker
BF-0000034 4 ohm speaker.
This is all you need to convert ps-2 5volt in diesel or steam with board in the tender. If the board is in the boiler then some very imaginative engineering to mount the board is in need. I have seen a steam loco with the new board held in with rubber silicone. Not sure I would have done this. If the board is in the boiler it may be better to use the PS-3 Steam upgrade and put the new board in the tender.
I am an ASC tech. and Authorized Service Center.