Gayle Jasper

Hi, I have a 1998 sl500 which the circuit board in the rear view mirror has fried. I wondered if anyone knows of a replacement board from another MB model.
The code on the board is 280-0045 rev j, the car is just the standard auto dimming mirror and is not motorised and does not have the garage opener.
Many thanks for any help given, I have done a little research and a board from a W140 appears to fit although a replacement mirror is close to the same cost of a R129 mirror so another cheaper alternative would be appreciated.