I have for sale an ASR computer for all 500E/E500 and 400E/E420 models (with ASR). This is a working unit.
Ideal as a spare unit or for testing purposes. These are not getting easier to find, particularly those that were originally used with the .036 and .034 models (as opposed to the 140 cars).
If you are a long-term owner of a 500E/E500, it's almost mandatory to have spares in hand for all four CAN computers + the DM for folks in the USA.
Price is $150 shipped ($135 + $15 shipping) anywhere in the US, via US Priority Mail.