MrBigg - if you want to try and repair, there are several threads on how to remove battery corrosion on circuit boards. They all involve acid (I use toilet bowler cleaner), 90% + isopropol alcohol, water, lots of soldering/desoldering - the corrosion makes solder removal difficult. You will need to remove a lot of components, because the corrosion travels along the circuit board runs amazingly far. On top of all of this, its possible to miss something, and you end up with a flakey board.

There used to be someone who repaired boards like this, but I think they stopped - too much work for such small rewards, but since this board is a game plan, someone may be willing to take on the task. However, with new boards available, I think that's your best route. Also, don't throw away the board. Cut off the battery and offer it up for sale. Someone may want it.

I would start with the bridges to the right of the card. There's several videos and steps on how to check them on Utube and on this website.